Worldsheet description of AdS3 moduli spaces

String theory has been a very active and fruitful field of theoretical research since several decades ago; during this period, the role of strings in anti de-Sitter spacetime has become central to the study of the holographic correspondence and in the search for black hole microstates. The purpose of this thesis is the derivation of an exact worldsheet description of string dynamics for a family of supersymmetric as well as non-supersymmetric deformations of the AdS3 x S3 x S3 x S1 spacetime, recently derived as solutions of IIB supergravity. Their worldsheet description is obtained as a gauged Wess-Zumino-Witten (WZW) model where asymmetric abelian group actions are gauged. In particular, the background metric tensor and antisymmetric form of the specific gauged WZW model are matched with a family of deformed AdS3 solutions. This exact description provides a useful tool to get insights into the problem of the stability of non-supersymmetric AdS3 solutions and more generally into the study of the holographic correspondence.