WAV is a container format for storing a record of a digitized audio stream without any compression. This format was developed by IBM and Microsoft in 1991 and was used in all versions of Windows. As the format uses audio streams without any compression, the files become very large in this format.
The OGG format is an open and free standard with no patent and license restrictions. Nowadays, there is no clear standard for this format. Also you should understand that OGG is just a container for video and sound, and may contain streams encoded by different audio and video codecs.