Glossary of terms
A list of technical terms commonly used in the field of digital forensics and computer science.
Digital Forensics
– The application of digital investigation and analysis techniques to determine potential legal evidence.
IP Address
– A name for a computer device on a Transmission Control Protocol (TCP)/Internet Protocol (IP) network. The TCP/IP is built into the operating system, and it is how data is transmitted from the Internet to the user.
Cookie
– A cookie is a message given to a Web browser by a Web server. Cookies are used to identify users and can possibly be used to prepare Customized Web pages for them. Cookies cannot spread viruses, nor can they access the hard drive.
Browser
– Short for “Web browser,” this software application can locate and display Web pages. The two most popular browsers are Netscape Navigator and Microsoft Internet Explorer. Both of these are graphical browsers, which means that they can display graphics as well as text.
Network
– A group of two or computer systems that are linked together.
Server
– A computer or device on a network that manages network resources. For example, a file server is a computer and storage device dedicated to storing files. Any user on the network can store files on the server. A print server is a computer that manages one or more printers, and a network server is a computer that manages network traffic. A database server is a computer system that processes database queries.
Servers are often dedicated, meaning that they perform no other tasks besides their server tasks. On multiprocessing operating systems, however, a single computer can execute several programs at once. A server in this case could refer to the program that is managing resources rather than the entire computer.
Operating System
– Every general-purpose computer must have an operating system to run other programs. Operating systems perform basic tasks such as recognizing input from the keyboard, sending output to the display screen, keeping track of files and directories on the disk, and controlling peripheral devices such as disk drives and printers.
For large systems, the operating system has even greater responsibilities and powers. It ensures that different programs and users running at the same time do not interfere with each other. The operating system is also responsible for security, so that unauthorized users do not access the system.
Local-Area Network (LAN)
– A computer network that spans a relatively small area. For example, most LANs are confined to a single building or group of buildings.
Wide-Area Network (WAN)
– A LAN that is connected to other LANs over any distance via telephone lines and radio waves.
Campus-Area Network (CAN)
– The computers are within a limited geographic area, such as a campus or military base.
Metropolitan-Area Network (MAN)
– A data network designed for a town or city.
Home-Area Network (HAN)
– A network contained within a user’s home that connects a person’s digital devices.
Secure Sockets Layer (SSL)
– A protocol developed by Netscape for transmitting private documents via the Internet. SSL works by using a public key to encrypt data that is transferred over the SSL connection. Both Netscape Navigator and Internet Explorer support SSL, and many Web sites use the protocol to obtain confidential user information such as credit card numbers.
Internet - The Internet is a massive network of networks or a networking infrastructure. It connects millions of computers together globally, forming a network in which any computer can communicate with any other computer as long as they are both connected to the Internet. Information that travels over the Internet does so via a variety of languages known as protocols.
World Wide Web
– The Web is not the Internet, but it is related to it. The Web is actually a way of accessing information over the medium of the Internet.
Protocols
– The rules and encoding specifications for sending data.
Delete
– To remove or erase, e.g. deleting a character means removing it from a file or erasing it from the display screen or a disk. A common misconception when deleting files is that they are also removed from the hard drive. However, data can still be retrieved from the hard drive even after the files have been deleted. The only way to completely erase a file with no trace is to overwrite the data.
Password
– A secret series of characters that enable a user to access a file, computer or program. The password helps ensure that unauthorized users do not access the computers. Ideally, the password should be something that nobody could guess. In practice, most people choose a password that is easy to remember such as their name or their initials. This may be why it is relatively easy to break into most computer systems.
Text File
– A file that holds text (word, sentences, paragraphs) and is usually stored as ASCII code. Most computers use ASCII codes to represent text, which makes it possible to transfer data from one computer to another. Objects that are not text include graphics, numbers and program code.
Media
– Objects on which data can be stored. These include hard disks, floppy disks, CD-ROMS and tapes. In computer networks, media refers to the cables linking workstations together.
Central Processing Unit (CPU)
– The CPU is the brains of the computer. Sometimes referred to as the processor or central processor, the CPU is where most calculations take place.
Circuit Board
– Sometimes abbreviated as PCB or printed circuit board, a circuit board is a thin plate on which chips and other electronic components are placed. Computers consist of one or more boards, often called cards or adapters.
Software
– Anything that can be stored electronically is software. Software exists as ideas, concepts, and symbols, and is often divided into two categories:
Systems Software
– This includes the operating system and all the utilities that enable the computer to function.
Applications Software
– Includes programs that do real work for users, e.g. word processors, spreadsheets and database management systems fall under this category.
Hardware
– Refers to objects that you can actually touch, like disks, disk drives, display screens, keyboards, printers, boards and chips.
Encryption
– The translation of data into a secret code. Encryption is the most effective way to achieve data security. To read an encrypted file, you must have access to a secret key or password that enables you to decrypt it. Unencrypted data is called plain text; encrypted data is referred to as cipher text.
Cipher Text
– Data that has been encrypted. Cipher text is unreadable until it has been converted into plain text (decrypted) with a key. Only a password or table can decipher encoded data.
Download
– To copy data (usually an entire file) from a main source to a peripheral device. The term is often used to describe the process of copying a file from an online service or bulletin board service to one's own computer. Downloading can also refer to copying a file from a network file server to a computer on the network.
Upload
– To copy a file from your own computer to another computer.