In music, a major scale and a minor scale that have the same tonic are called parallel keys and are said to be in a parallel relationship. The parallel minor or tonic minor of a particular major key is the minor key based on the same tonic; similarly the parallel major has the same tonic as the minor key (from the Greek, para alleilos, "beside each other ''). For example, G major and G minor have different modes but both have the same tonic, G; so we say that G minor is the parallel minor of G major. In contrast, a major scale and a minor scale that have the same key signature (and therefore different tonics) are called relative keys.
what type of keys have the same tonic but different key signatures
parallel keys