Question

what is dsl .Ezplain briefly

Answer 1

Digital subscriber line is a family of technologies that are used to transmit digital data over telephone lines. In telecommunications marketing, the term DSL is widely understood to mean asymmetric digital subscriber line, the most commonly installed DSL technology, for Internet access.

Answer 2

DSL (Digital Subscriber Line) is a technology for bringing high- bandwidthinformation to homes and small businesses over ordinary copper telephone lines. xDSL refers to different variations of DSL, such as ADSL, HDSL, and RADSL. Assuming your home or small business is close enough to a telephone company central office that offers DSL service, you may be able to receive data at rates up to 6.1 megabits(millions of bits) per second (of a theoretical 8.448 megabits per second), enabling continuous transmission of motion video, audio, and even 3-D effects. More typically, individual connections will provide from 1.544 Mbps to 512 Kbps downstream and about 128 Kbps upstream. A DSL line can carry both data and voice signals and the data part of the line is continuously connected. DSL installations began in 1998 and will continue at a greatly increased pace through the next decade in a number of communities in the U.S. and elsewhere. Compaq, Intel, and Microsoft working with telephone companies have developed a standard and easier-to-install form of ADSL called G.Lite that is accelerating deployment. DSL is expected to replace ISDN in many areas and to compete with the cable modem in bringing multimedia and 3-D to homes and small businesses.

Briefly means that you are not expanding the answer beyond the requested core.
Assume someone asks you “what’s a star?”. Based on your knowledge you might expand in all the various types of stars there are, how they come to be and how they end. But the brief answer to the question is that a star is the visible result of fusion of hydrogen and helium which happens due to gravity.

This however might not be sufficient for your audience.
You can expand: when a large amount of particles such as hydrogen and helium are close together they will clump together. When particles clump together the temperature will rise. When an enormous amount of particles clumps together the heat will increase significant. At some point the heat generated by the force of clumping together will cause atoms to fuse, which means atoms turn into different, heavier, atoms, and in this fusion process emit some radiation as result. The light we see is a fraction of this radiation.

Depending on audience the first sentence might be sufficient, the addition of the additional paragraph might be sufficient or you need to provide far more information, in which case it’s not brief anymore.