Text to Model (T2M) transformation is about parsing concrete syntax and creating an internal representation that is easier to handle → see “xtext and xtend”
Model to Model (M2M) transformation is about working with the internal representation → see “startransformer and cts”
Model to Text (M2T) transformation (also known as “code generation”) is about creating concrete syntax from the internal representation → see “xpand, jet, etl”