Halide perovskites are promising materials for light-emitting and light-harvesting applications. In this context, two-dimensional perovskites such as nanoplatelets or Ruddlesden-Popper and Dion-Jacobson layered structures are important because of their structural flexibility, electronic confinement, and better stability. This review article brings forth an extensive overview of the recent developments of two-dimensional halide perovskites both in the colloidal and non-colloidal forms. We outline the strategy to synthesize and control the shape and discuss different crystalline phases and optoelectronic properties. We review the applications of two-dimensional perovskites in solar cells, light-emitting diodes, lasers, photodetectors, and photocatalysis. Besides, we also emphasize the moisture, thermal, and photostability of these materials in comparison to their three-dimensional analogs.