Obtain could be a synonym for acquire, but while the latter means to get, the former means to get hold of, to gain possession of something. In linguistics, it means to achieve native-like level of language knowledge, however, do not confuse it with language learning. In military context, it refers to location and track with a detector. Skills are acquired but a degree, for instance, is obtained. Obtain with an object, means to come into possession of something trough an effort or by a request. Without an object, it means to be prevalent or customary.
