Welding produces a solid connection between two pieces, called a weld joint. A weld joint is the junction of the edges or surfaces of parts that have been joined by welding.
Mostly, five basic types of joints are used for bringing two parts together for joining. Five basic types are butt joint, lap joint, corner joint, edge joint and Tee joint.

1. Butt joint
In this joint type, the parts lie in the same plane and are joined at their edges.
2. Corner joint
The parts in a corner joint form a right angle and are joined at the corner of the angle.
3. Lap joint
When two parts or surfaces overlap each other then the joint made is known as lap joint.
4. Tee joint
In a tee joint, one part is perpendicular to the other in the approximate shape of the letter ‘‘T.’’
5. Edge joint
The parts in an edge joint are parallel with at least one of their edges in common, and the joint is made at the common edge(s).