Treasury bills

Treasury bills are debt borrowing by the government (like loan stock issued by companies except that they are short term borrowing). Treasury stock are shares in a company that have been bought back by the company but have not been cancelled - they are not relevant for Paper FM.

sir with regards to treasury bills ... why would the government burrow money from companies sir

The government doesn't borrow money only from companies. All governments borrow money so as to help finance government spending. They issue debt just like companies issue debt and anyone can invest in the debt (and receive interest) - not only companies.

oh thank you sir plus im also confused with the terms issueing debt and investing in debt issuing debt is the party who burrows the money or funds and investing in debt is the party lending or giving funds or money . am i correct sir ? ( if im not mistaken )

Correct.