What is a interdenominational church?

Answer 1

The prefix "inter" means "between" or "among". Denomination usually refer to the various Christian (usually not Catholic) denominations such as Presbyterian, Baptist, AoG etc. So an interdenominational church would include people from various denominations with all the various emphasis of beliefs. That is, emphasis of beliefs that distinguish denominations. There is a common set of essential doctrines amongst the denominations that enable this to occur. The interdenominational church finds unity in this common set of essential doctrines.

Answer 2

All Christian denomnations have common beliefs in God, the divinity of Jesus, the Trinity, the crucifixion, resurrection and ascension and so on. However, they do differ in peripheral beliefs (like whether baptism is by sprinking or issersion, or the nature of the Virgin Mary etc). Because their core beliefs are in comon with all other denominations, it is perfectly possible to have a church that is not affiliated to just one denomination.

Interdenominational churches are churches that have affiliations to more than one denomination. As an example I once attended an Anglican/Methodist Church, and taught in a Roman Catholic/Anglican school. Just down the road from my church was an Anglican/Methodist/Baptist/United Reformed Church that was multidenominational.

These churches sometimes have services that are faithful to one tradition on a rota basis, or sometimes have services that reflect the best from all the denominations that make up the church. In the UK they are becoming more prevalent and are known as 'Local Ecumenical Partnerships' (LEPs) and sometimes these LEPs are loose partnerships spread over two or more churches, sometimes they are two or more denominations that simply use the same building, but more frequently they are partnerships where total integration of the denominations is the norm.