An analogue telephone line enables, via an installed wall socket, the connection of an analogue device, such as a telephone, modem or fax machine, to the telephone network.
Although the oldest technology on the market it is still the backbone of telecoms in UK as all ADSL and Fibre to the cabinet, lift lines, alarm and Redcare lines as well as other services depend on it.
An Analogue line is a single copper cable that is run in to your building by your line provider. Before ADSL was available Analogue lines were
used for both voice and data. Now these lines are used mainly just for voice calls as the total bandwidth available is only 56k. ADSL can give you up to 8meg of data transfer and now with ADSL2 services available you can get speeds of up to 24MEG. To utilise ADSL or broadband you will still need to have an analogue line.
Analogue lines can be used as single lines or can be effectively spliced together to give you multiple lines that share the same telephone number. Generally for a small office Analogue lines are fine because they are not expensive to install and the line rentals are not relatively cheap. When ISDN2 was introduced lots of businesses upgraded so that they could have Caller ID. This has always been available on Analogue lines but would not work on most Telephone Systems. Now there are very few systems available that do not support Caller ID on analogue lines.