What Is Call detail record

Call detail record as its name tells that it is a system that stores the significant information about a call.  In old days the call records were managed manually by the operators that were appointed by the telephone exchange. 
By the advancement of technology, computer science has made it possible to do all this hard work automatically. Now days this all is done by automated systems that are attached to every phone line.  They are used to keep record for a lot of things that are attached with a single phone line. Every call is monitored in terms of its length, source date and time.

This is done by complex computer software developed especially for this purpose. Giving you example of a single phone line that how the call detail record works. Whenever a call comes in to connect to a particular number at the very moment the automatic system tracks it back to its source and notes it location and number. Then if it is answered then the duration for which the call was on line is noted by a timer that turns on. At the end when the call is terminated the timer stops and the total time of the call is noted. The date of the call and the starting time is noted with all other information.

This process is repeated for each and every call and for every number in a particular system. This is stored in the data base that is available at the phone exchange. Specialized software and algorithms are designed to do all this work and for millions of connections each day. These records are very necessary to calculate the bills and charges for the user every month and also they are helpful in tracking something particular for a special reason.