BSNL full form is Bharat Sanchar Nigam Limited which was the name that it got once its divisions from CellOne were changed. CellOne was the primary name or the old name of BSNL before it was converted by the government into BSNL.
BSNL as we all know it is one of the largest Telecom service providers in India and more importantly it is a government owned property. It is placed under the Government property of the Department of Telecommunication and the Ministry of Communication. Some of you might be using BSNL services like their landline phones, Wi-Fi or even BSNL Sims.