Join

Join may refer to:

Join (law), to include additional counts or additional defendants on an indictment
In mathematics:
- Join (mathematics), a least upper bound of sets orders in lattice theory
- Join (topology), an operation combining two topological spaces
- Join (sigma algebra), a refinement of sigma algebras
- Join (algebraic geometry), a union of lines between two varieties
In computing:
- Join (relational algebra), a binary operation on tuples corresponding to the relation join of SQL
  - Join (SQL), relational join, a binary operation on SQL and relational database tables
  - join (Unix), a Unix command similar to relational join
- Join-calculus, a process calculus developed at INRIA for the design of distributed programming languages
  - Join-pattern, generalization of Join-calculus
  - Joins (concurrency library), a concurrent computing API from Microsoft Research
Join Network Studio of NENU, a non-profit organization of Northeast Normal University
Joins.com, the website for South Korean newspaper JoongAng Ilbo
Joining (woodworking), woodworking processes of combining two or more pieces of wood together, generally through the use of nails or screws
Joining (metalworking), metalworking processes which combine two or more pieces of metal together, typically by the use of screws or welding or a single

See also