(1) An SQL relational operation that allows retrieval of data from two or more tables based on matching column values. See also equijoin, full outer join, inner join, left outer join, outer join, right outer join, star join.
(2) The configuration on an incoming link that determines the behavior of the link.
(3) A process element that recombines and synchronizes parallel processing paths after a decision or fork. A join waits for input to arrive at each of its incoming branches before permitting the process to continue.
(4) In UML diagrams, a node that models two or more flows of control that unite into a single flow.
(5) To become a new member of an entity such as a cluster.