Computer Science Tutors for Class 6 - 8 in Howrah

Difference between RAM and ROM:

RAM, which stands for random access memory, and ROM, which stands for read-only memory, are both present in the computer. 

RAM is volatile memory that temporarily stores the files you are working on. ROM is non-volatile memory that permanently stores instructions for your computer.

RAM (Random Access Memory):

RAM is volatile memory, which means that the information temporarily stored in the module is erased when you restart or shut down your computer. Because the information is stored electrically on transistors, when there is no electric current, the data disappears. Each time you request a file or information, it is retrieved either from the computer's storage disk or the internet. The data is stored in RAM, so each time you switch from one program or page to another, the information is instantly available. When the computer is shut down, the memory is cleared until the process begins again. Volatile memory can be changed, upgraded, or expanded easily by users.

ROM (Read Only Memory):

ROM stands for non-volatile memory in computers., which means the information is permanently stored on the chip. The memory does not depend on an electric current to save data, instead, data is written to individual cells using binary code. Non-volatile memory is used for parts of the computer that do not change, such as the initial boot-up portion of the software, or the firmware instructions that make your printer run. Turning off the computer does not have any effect on ROM. Non-volatile memory cannot be changed by users.

Animals that live on both land and in water are called Amphibians. Eg. Frog, Tortoise, Crocodile.

Lan is local area network and Wan is wide area network. When a group of computers are connected in a small area like the building, office it is local area network. When a group of computers are connected over a large area it is Wan.

Xerophyte Plant:

A xerophyte (xero meaning dry, phyte meaning plant) is a plant that is able to survive in an environment with little availability of water or moisture. Plants like the cacti and other succulents are typically found in deserts where low rainfall is the normal phenomenon, but few xerophytes can also be found in moist habitats such as tropical forests, exploiting niches where water supplies are limited or too intermittent for mesophytic plants. Coniferous Forest Plants:

Evergreen cone-shaped trees, growing needle- or scale-like leaves are called conifers. Most trees growing in these forest regions are cone-bearing gymnosperms, meaning their seeds are bore exposed, without any outer enclosure, in the form of cones. Although nowhere as rich as temperate forests and tropical rainforests, the conifers have adapted well to thrive in the unconventional growing conditions of the coniferous forests.

There are over 600 extant species of conifers, which are categorized into different groups depending on their foliage shape and needle type.

Third Generation of Computers:

The Third generation computers were faster, smarter, and user friendly compared to previous computers.

These generations of computers were far more advanced than their counterparts as they used and utilized Integrated Circuit IC as their main component.

The IC was advanced technology at that time and therefore increased speed and efficiency, outsmarting the other computers in the market.

Fourth Generation of Computers:

These 4th generations of computers were more reliable and user-friendly than other generations.

They used microprocessors as their main component and installed them in their circuit, which enhanced the overall performance like speed, accuracy, efficiency, and reliability.

The microprocessor increased the computer’s speed, making them multitask, and multiprogramming eventually increased the overall performance.

• The history of computer starts with the simple tool all we have heard  about,  "The Abacus".
• Let us learn how and when did it lead to the invention of Computers.
• The initial computers did not have any monitor and memory. The abacus - adding machine is a wooden rack holding horizontal wires with beads strung on them. It was invented in Babylon around 2000 years ago.
•  In 1822, Charles Babbage, a professor of mathematics, designed an automatic mechanical machine called difference engine, which is a type of counting machine. He also introduced another machine called Analytical Engine which could store information on punched cards.  Babbage invented all necessary parts that modern computer use, but it wasn't until 1940 that modern computers were introduced. Charles Babbage is known as the father of the computer.

Generation of computers:

   Since their invention, Computers have evolved and advanced quickly. Commonly we can group the developments in computers into five generations. Change in technology is referred to be as 'Generation'. All the generations are explained in the following points.    First Generation (1940-1956):

• First-generation computers, such as UNIVAC - I (Universal Automatic Computer - I) and ENIAC (Electronic Numerical Integrator Analyzer and Computer), were huge.
• They took huge space because they used vacuum tubes for circuits and magnetic drums for memory storage.
• They consumed a large amount of electricity and generated a lot of heat.
• They were very expensive.
• They used machine language.

Second Generation (1956-1963):

• Second-generation computers used two types of devices namely transistors and magnetic core.
• Transistors replaced vacuum tubes in circuits, and the magnetic core replaced magnetic drum for memory storage.
• Second-generation computers outwitted first-generation computers due to transistors, making the computers smaller in size, faster (microseconds), cheaper, energy-efficient and more reliable.
• In second-generation computers, transistors replaced the vacuum tubes but still generated a lot of heat that caused damage to the computers but comparatively lesser than the first-generation.
• Instead of a Machine language, Assembly language was used.
• A translator is used to convert the assembly language into machine language. This translator is called as an assembler.
• Examples - IBM - 1920,IBM - 1401, etc.,

Third Generation (1964-1971): IBM - 360

• The third-generation computers were the improved version of second-generation computers, where the transistors were replaced by Integrated Circuits (IC).
• Integrated circuits were silicon chips where multiple transistors were placed. This reduced the size of the computers massively.
• They were cheaper than the previous generation.
• This generation of computers used parallel processing to improve processing efficiency.
• These computers could calculate the data in nanoseconds.
• For Programming, high-level languages were used.
• These computers were general-purpose computers and used for commercial purpose also.
• Operating system and other application software were introduced and used.
• Examples - IBM - 360series, CDC - 1700, etc.,

Fourth Generation (1971-Present):

• Fourth-generation computers were introduced after third-generation computers, which generally used microprocessor.
• A Microprocessor generally consists of thousands of integrated circuits built on a single chip known as a silicon chip.
• Very Large Scale Integration (VLSI) technology used. Billion of circuits per cubic foot.
• Computation speed - Picoseconds
• Smaller in size, faster and more reliable
• They use less electricity and generating less heat.
• Examples - Apple, Cray - 1, etc.,

Fifth Generation (Present):

• After the invention of fourth-generation computers, the fifth-generation computers were introduced.
• The fifth-generation computers or modern-day computers are based on Artificial Intelligence (AI) and are still in their developmental phase. Japan invented the FGCS (Fifth Generation Computer System) in 1982.
• This generation computer is based on microelectronic technologies with high computing speeds and parallel processing.
• Example - IBM notebooks, PARAM - 10000, etc.,

When the goto statement is encountered, the control of the program jumps to label: and starts executing the code.

EG: GOTO LABEL;

.............................

.............................

LABEL:

STATEMENT;

Amphoteric oxide : The oxides of elements which can react with both acid and base to give salt and water .Here Zno is amphoteric oxidebecause it has dual nature of reaction that is it can reacts with both acid and base to form salt and water ZnO+Acid-Salt+water ZnO+Base-salt+water.

Internet Service Provider (ISP):

 An internet service provider (ISP) is a company that provides web access to both businesses  and consumers.

• ISPs may also provide other services such as email services, domain registration, web hosting, and browser services.
• An ISP is considered to be an information service provider, storage service provider, internet network service provider (INSP), or a mix of all of them.
• Internet use has evolved from only those with university or government accounts having access to nearly everyone having access, whether it's paid or free.
• Access has gone from dial-up connections to high-speed broadband technology.

As noted above, internet service providers primarily provide their customers access to the internet—plain access providers that just handle the traffic between the individual and the internet as a whole. But there may also be other services bundled in depending on the customer's location and availability. Some of these services include:

• Email services
• Web hosting services
• Domain registration
• Browser and software packages 

  WORLD WIDE WEB: The World Wide Web (abbreviated as the Web or WWW) is a system of Internet servers that supports hypertext to access several Internet protocols on a single interface. Almost every protocol type available on the Internet is accessible on the Web. This includes e-mail, FTP, Telnet, and Usenet News. In addition to these, the World Wide Web has its own protocol that is   Hyper Text Transfer Protocol, or HTTP.

  The operation of the Web relies primarily on hypertext as its means of information retrieval. Hyper Text is a document containing words that connect to other documents. These words are called   links and are selectable by the user. A single hypertext document can contain links to many documents. In the context of the Web, words or graphics may serve as links to other documents, images, video, and sound. Links may or may not follow a logical path, as each connection is programmed by the creator of the source document. Overall, the Web contains a complex virtual web of connections among a vast number of documents, graphics, videos, and sounds.

  Producing hypertext for the Web is accomplished by creating documents with a language called Hyper Text Markup Language, or HTML. With HTML, tags are placed within the text to accomplish document formatting, visual features such as font size, italics and bold, and the creation of hypertext links. Graphics and multimedia may also be incorporated into an HTML document. HTML is an evolving language, with new tags being added as each upgrade of the language is developed and released. The World Wide Web Consortium (W3C), led by Web founder Tim Berners-Lee, coordinates the efforts of standardizing HTML. The W3C now calls the language XHTML and considers it to be an application of the XML language standard.

  E-MAIL: Electronic mail, or e-mail, allows computer users locally and worldwide to exchange messages. Each user of e-mail has a mailbox address to which messages are sent. Messages sent through e-mail can arrive within a matter of seconds.

  A powerful aspect of e-mail is the option to send electronic files to a person’s e-mail address. Non-ASCII files, known as binary files, may be attached to e-mail messages. These files are referred to as MIME attachments.

  MIME stands for Multimedia Internet Mail Extension, and was developed to help e-mail software handle a variety of file types. For example, a document created in Microsoft Word can be attached to an e-mail message and retrieved by the recipient with the appropriate e-mail program. Many e-mail programs, including Eudora, Netscape Messenger, and Microsoft Outlook, offer the ability to read files written in HTML, which is itself a MIME type.

A homepage is the front page of a website which contains link to other pages. This is the page that shows up by default when someone accesses a URL from their browser.

Any page other than the home page of a website is the webpage.It is a single page that is part of a website.