In differential geometry and complex geometry, a complex manifold is a manifold with a complex structure, that is an atlas of charts to the open unit disc in the complex coordinate space C n {\displaystyle \mathbb {C} ^{n}} , such that the transition maps are holomorphic.
The term "complex manifold" is variously used to mean a complex manifold in the sense above (which can be specified as an integrable complex manifold) or an almost complex manifold.