For most stock trades, settlement occurs two business days after the day the order executes, or T+2 (trade date plus two days). For example, if you were to execute an order on Monday, it would typically settle on Wednesday. For some products, such as mutual funds, settlement occurs on a different timeline.
Today, using modern technology, a transaction is electronically processed in less time. Most stocks and bonds settle within two business days after the transaction date. This two-day window is called the T+2. Government bills, bonds, and options settle the next business day.