Window installation is the process of fitting new windows into a building or replacing old ones. This involves measuring the window openings, selecting the appropriate window type, and ensuring proper sealing to prevent air and water leaks. The installation typically requires tools like a level, caulk, and screws. Professionals or skilled DIYers can perform the task, but it's essential to follow safety guidelines and local building codes. Proper installation enhances energy efficiency and improves the overall appearance of a home.