Digital Subscriber Line (DSL): A type of communication medium used for transmitting digital data over telephone lines. It allows for fast data transfer speeds, providing an internet service that is significantly faster than traditional dial-up. This technology makes use of standard copper phone lines and is widely used in homes and businesses around the world.

Direct Evidence: In legal terms, direct evidence is any material or information that directly proves a fact. It is evidence that, if believed, immediately establishes the truth of a fact without inference or presumption and does not require further support or corroboration. Examples of direct evidence include eyewitness testimony, a confession, or a video recording of the event in question. Direct evidence can be contrasted with circumstantial evidence, which suggests the truth of a fact indirectly through inference.

Directional Antenna: A type of antenna that is designed to focus the radio signal in a particular direction. Unlike omnidirectional antennas that transmit and receive signals in all directions, directional antennas concentrate the signal in a specific area, which can significantly extend the range and improve the quality of the transmission. They are commonly used for point-to-point communication, including radio and television broadcasting, cellular communications, satellite communication, and wireless bridges. The focused signal also adds the benefit of reduced interference from unwanted sources outside of the target path.

Directive: A formal instruction, order, or policy issued by an authority. It sets a course of action, procedure, or standard to be followed. Directives can be used to implement and enforce compliance with laws and regulations, and in an organizational context, they might outline specific requirements related to information protection, user behavior, or the use of systems and networks.

Directory: In the context of computing, a directory is a file system cataloging structure that contains references to other computer files and possibly other directories. On many computers, directories are known as folders. In operating systems, directories are used to organize files in a hierarchical structure, providing a convenient means to access data stored within the system. Additionally, in networking, a directory refers to a service that stores, organizes, and provides access to information about network resources and users, such as a Lightweight Directory Access Protocol (LDAP) directory.

Directory Service: A system or software that stores and manages directories of information, such as user accounts or network resources. It is often used in the context of computer networks to provide centralized access and management of directory information. For example, a directory service may be used to manage user accounts in an Active Directory environment or to provide access to shared resources in a network.