____________
| |
-INPUT-->| COMPUTER |---> OUTPUT
|__________|
A typically electric device used for calculations of varying sort.
A typical home computer has a keyboard - a device for typing letters (input), and a monitor - a device for showing images (output). The larger, difficult-to-move home computers are PC (personal computers) and a small, portable ones are laptops.
The process of manipulating the information on a computer is programming. The physical parts of a computer are hardware and programmable parts are software. Software on almost all computers is stored digitally (whole numbers), in binary using boolean logic. The smallest unit of memory in a computer is a bit(b). 8 bits create a byte(B).
..........:::::::::::|||||||||| .SOFTWARE.::FIRMWARE:|HARDWARE| ..........:::::::::::||||||||||
Computers operate using transistors and boolean logic. Data on a computer is stored in memory, which categorizes it into files.
_____ _____ ______ __________
| | _______ | | | | | |
| CPU | <---> | cache | <---> | RAM | <---> | disk | <---> | Internet |
|_____| """"""" |_____| |______| |__________|
small big huge gigantic
fast slowish super slow extremely slow
Software preinstalled on a device from factory and provides most essential functionalities. It works with hardware at the closes level, usually installed on some kind of memory that's not easy to rewrite. Certain simple devices, like mp3 players or remote controls, only have firmware.
OS (operating system) is a program installed on top of the firmware that is a platform for running other programs by allocating the appropriate resources to them. An operating system consists of a kernel (the core) and a userland, which constists on primary programs running on top of the kernel, such as a compiler. Programs in the userland refer to the kernel using system calls. A bootloader (which may have parts in hardware and parts in firmware) is the tool that loads the operating system when the computer is booted.
A file is a separate chunk of data designated to be/do one thing. A file can be an program, an image, a video. A data is always the same piece of code, the file extension (.txt, .png...) lets the computer know which program opens it.
Compression is encoding data in a different way using an algorithm to make it take less memory while keeping all the original information. The reverse process is decompression. The ratio of the compressed data size to the original data sazed is a compression ratio (lower is better). It is used in data/files with a lot of redundancy such as video, but can also be done for things like RAM. Compression can be lossless or lossy (drops information of of low importance). A definition list in an encyclopedia is an example of non-computer compression.