Bar clamps are versatile tools used in woodworking and metalworking to hold pieces together securely while glue dries or during assembly. They consist of a long metal or wooden bar with adjustable arms that can be tightened to apply pressure on the workpieces. These clamps come in various sizes and styles, making them suitable for different projects. They are particularly useful for creating strong joints in furniture making or cabinetry. The ease of adjustment allows for quick setup, making bar clamps a favorite among both professionals and DIY enthusiasts.