A Treasury bill, often referred to as a T-bill, is a short-term debt security issued by the government of a country, usually with a maturity of less than one year. These securities are considered to be one of the safest investments available because they are backed by the full faith and credit of the government.

In the United States, Treasury bills are issued by the U.S. Department of the Treasury to fund the government's short-term borrowing needs. They are sold through competitive and non-competitive bidding at regularly scheduled auctions.

Here are a few key features of Treasury bills:

Maturity: T-bills have maturities of 4 weeks, 13 weeks (3 months), 26 weeks (6 months), or 52 weeks (1 year). Investors can choose to invest in T-bills with different maturity periods based on their investment goals and preferences.

Issuance and Auctions: T-bills are typically issued on a regular schedule and are sold at auction. The auction process involves both competitive and non-competitive bidding. Competitive bidders specify the yield they are willing to accept, while non-competitive bidders agree to accept the average yield of the competitive bids.

Discounted Pricing: Treasury bills are sold at a discount to their face value, meaning investors purchase them for a price lower than the amount they will receive at maturity. The difference between the purchase price and the face value represents the investor's return on investment.

Fixed Interest Rate: Unlike other fixed-income securities such as bonds, T-bills do not pay periodic interest payments. Instead, investors earn a return through the difference between the purchase price and the face value at maturity.

Liquidity: Treasury bills are highly liquid investments, meaning they can be easily bought and sold in the secondary market before their maturity date.