Government securities (G-Secs) are debt instruments issued by the government. When you own a g-sec, you are lending to the government. Long-term g-secs offer periodic interest payments, while short-term g-secs are issued at a discount and redeemed at par.
Since governments rarely default on their debt obligations, g-secs are considered to be credit risk-free. The Indian government has never defaulted on its debt obligations.
Read more: Government Securities