How does bits and bytes work

Let's say you find a file online that is 17 megabytes MB in size, and you want to download it using your 17 megabit per second Mbps broadband connection. This won't take one second; it will take eight times one second because a megabyte is eight times bigger than a megabit.

So in theory — and with a perfectly consistent speed — it should take eight seconds to download. Before you start reaching for your calculator, read our guide to download times.

We've pulled together a list of the most common broadband speeds and file sizes to give you an idea of how long it will take to download films, TV series, songs and more.

From how it's written. A byte is an uppercase 'B' and a bit is a lowercase 'b'. If it says MB, all capitals, then it is a megabyte. If it says Mb, then it is a megabit. There is one exception to this, of course, and it is the symbol for kilobit, which is 'kb', all lowercase.

But these file sizes are so small nowadays that you shouldn't really see much of them. Each action of the CPU can be thought of as occupying one cycle - although most modern CPUs can perform several tasks at the same time. Therefore the greater the number of cycles per second, the faster the computer. The third factor is the size of the words that both the microprocessor and the buses can accommodate go back to the previous segment on computer architecture if you need to refresh your memory about these.

You may sometimes hear people refer to a computer - or particularly a games console - as a bit, bit or bit machine. These terms refer to the size of word that the microprocessor can manipulate.

The larger the word size, the more information each word can contain. A bit word can contain twice the data of a bit word. Therefore increasing the word size improves both the complexity more data can be manipulated and the speed because it takes the same time to interpret each word. A fourth factor that affects a computer's power is the amount of memory, or RAM, available.

RAM acts as the computer's working memory, so it contains the information the computer needs for its current session. This will include various operating system commands e. Microsoft Word with two documents open , current display configurations e.

An increase in the size of the RAM increases the amount of data it can store at any one time. This improves the complexity of the computer because it can run programs that require a lot of data to be handled, and several programs can be run simultaneously. It also increases the speed of the computer because when the RAM becomes full the computer will temporarily store data on the hard disk.

This will be retrieved when it is required, which takes more time than having it currently available in memory. So more RAM provides more speed. The power of computers now is such that their performance is fast enough to meet most needs, and the software you use does not really necessitate the rapid upgrade it once did.

This gradual easing of demand poses a problem for the computer industry, and we shall look at its effect on the perception of computers later in the module. In the next segment you will look at the different types of computer, including PCs: Types of computer. This module is mainly concerned with computers based on microprocessors, called microcomputers or personal computers PCs.

Later sections of this module will examine the PC in detail and the types of software used by them. There are other types of computer though, and you will need to be aware of these. However, don't get too bogged down in the details - the important thing is that you have an appreciation of the different types of computers and the tasks they might perform.

Mainframes were the dominant form of computing before microcomputers. They are usually very expensive, powerful and operate specialist software. Mainframes are typically used by large companies, public authorities and universities for their data handling tasks. These tasks are typically:. File maintenance : This is perhaps the most common use of mainframes.

Maintaining records is a huge task for institutions. Records can contain information on sales, credit card status, payroll details, social security details, health records, stock inventory, etc. These either need to be accessed by different people in real-time for instance a travel agent booking an airline ticket or updated in batches for instance warehouse stock levels at the end of each day.

It is necessary in such cases to have the data stored centrally and then accessible by those who need it. A lot of minicomputers are now capable of performing these tasks in medium-sized companies.

Simulations : Many physical and engineering problems cannot be solved without the help of complex computer simulations. These require intensive mathematical work, and so take advantage of a mainframe's computational power.

Examples include weather forecasting, or calculating the position of astronomical bodies with extreme accuracy. Many minicomputers or workstations are now used for this type of problem. General purpose : Many universities used a mainframe to act as a general purpose computing facility.

Each user can then be given their own area on the mainframe to store files, and different departments can use its resources to perform different tasks, e. PCs are now used to perform many of these tasks. You will have noticed that after each task I mentioned that other types of computer could now be found performing these tasks. This indicates that the general growth in the mainframe area has slowed and is even in decline, as smaller computers have become more powerful.

Mainframes are still required by many institutions, however, to perform large data handling tasks. They are particularly useful when data needs to be held centrally, with different people needing access to it.

This is illustrated below:. Minicomputers are powerful, special-purpose computers. However, they have become increasingly powerful and have replaced mainframes for many functions. Plant control : Many industrial plants require a central computing facility to collect data from various sensors and then to act accordingly. For example, in a chemical engineering plant, as the pressure in one vat increases the computer registers this, and opens a release valve slightly while also adjusting the boiler temperature.

Network control : Many computer networks need a central computer which provides storage space and controls the network using special network software. This is known as a server. The other computers which access the server are called clients. Such machines can also act as the interface to the Internet, accepting Internet messages and hosting e-mail and World Wide Web facilities.

Powerful PCs can also be used to perform these functions. Databases : As mentioned above, the role of mainframes in file maintenance is increasingly being taken by minicomputers. Minicomputers can hold databases of records which appropriate people can access.

For the general public it is PCs which tend to symbolize computers. With the growth in networking computers in most institutions the role of minicomputers has grown. It is in this market that some of the largest software companies, such as Novell who provide networking software and Oracle who supply database software, do most of their business.

Workstations are based on specialized microprocessors and can be thought of as powerful PCs. They are typically used for specialist engineering tasks. Workstations use a special type of microprocessor known as a RISC reduced instruction set computer chip.

This technology, developed at IBM, removes many of the complex instructions from a microprocessor and has instead a set of basic instructions, which perform their tasks very quickly. This approach increases the speed and the power of the microprocessor, particularly when dealing with numerical problems.

The workstation market is dominated by SUN Microsystems. These technologies allow engineers to design complex machine parts without having to produce an actual physical model. The necessary complex, 3-D graphics require a lot of computing power and good quality video capabilities. Simulations : Performing simulations of processes, such as the behaviour of an industrial plant, requires considerable computing power.

Multitask programming : Any complex programming which is deemed to require more power than is offered by a PC, and which needs to perform more than one task at a time called multitasking , is often performed on a workstation.

Microcomputers are based on a microprocessor and are intended for individual use; hence they are called personal computers, or PCs. They were initially standalone machines, but are increasingly connected to a network. They are ideal for tasks such as those listed below where the user requires individual computing power. Word processing : Word processing programs allow a user to produce professional-looking documents, with different fonts, styles and pictures.

The production of complex and attractive documents is much easier with the use of word processing software than it was in the days of the typewriter. Spreadsheets : Spreadsheets allow a user to create mathematical models. Desktop publishing : This allows people to create drawings, manipulate images and combine them with text to produce professional graphic design work, for instance magazine layouts, posters, book covers, etc. Games : Although this may seem a non-serious use of computers, games represent a large market.

By making use of the PC's computing power very good quality graphics and complex game play can be achieved. Servers : As mentioned above, many powerful PCs are now being used as servers to control a network.

Generally the tasks performed by the mainframes have been taken over by minicomputers. PCs initially created a new type of usage for the computer; for instance, spreadsheets and desktop publishing took over from activities previously performed by hand.

The speed of transferring data from network to network continues to grow as both file sizes, and computing components can handle more data. Every byte consists of eight bits. Not exactly. Remember, computers operate using the binary system. That means hard drives, memory, and bandwidth are measured in powers of two.

For example, the IP address The encoding of that IP address in bits looks like this:. As you can see, that 1, number keeps popping up! Say you were to convert 4 kilobytes into bits. These numbers lead to confusion among consumers. For example, when you purchase a 1 terabyte hard drive, it has about 8 trillion bits.

Well, manufacturers are assuming a rounded megabytes per gigabyte, while computers use 1, On top of this, your operating system needs a small amount of space on the disk. Even with all this information, computing can still be confusing. The beauty of computing is that it is a structured system with static rules.

Technology always advances, but the principles stay the same. You might hear an advertisement that says, "This computer has a bit Pentium processor with 64 megabytes of RAM and 2. In this article, we will discuss bits and bytes so that you have a complete understanding. The easiest way to understand bits is to compare them to something you know: digits.

A digit is a single place that can hold numerical values between 0 and 9. Digits are normally combined together in groups to create larger numbers. For example, 6, has four digits. It is understood that in the number 6,, the 7 is filling the "1s place," while the 5 is filling the 10s place, the 3 is filling the s place and the 6 is filling the 1,s place.