A multi-site church is a church or congregation which holds services at two or more locations.
The most common arrangement is for each location to have separate singing, after which the sermon is broadcast from one location (usually the original location which is almost always the largest) to the others. In other cases, a common sermon may be preached at all locations, with a different speaker at each (though the senior pastor is almost always at the largest location).
The concept started in 1998 in California with North Coast Church, and began taking off in the 2000's when South Carolina-based Seacoast Church (unable to gain local government approval for expansion of its facility) opened an off-site location.
The largest multi-site church operation in America is Life.Church, based in Oklahoma City: the church (with an estimated attendance of over 50,000) operates 32 campuses across ten states, with the majority of the campuses located in the Oklahoma City and Tulsa metro areas.
A multi-site church may also have multiple services as well: a notable example involves Southlake, Texas based Gateway Church, which holds 27 services over its six campus locations (along with streaming services live on the Internet).