It depends on what the camera can deliver. For older cameras it was mainly jpeg and mjpeg. For newer cameras with a higher resolution like 720p, 1080p and above they use h.264 to compress the data stream.
The protocol used for:
-JPEG is http. Only images/video.
-MJPEG is http. Only images/video.
-h.264 (compressed format) is rtsp. Will give video and audio.
Normally http use port 80 and rtsp use port 554. But, this can be changed in the camera configuration and ports like 88 for http and 10554 for rtsp is common. But it is strongly recommended to use the standard ports.
Just for information, the next generation of compression is here and called h.265 for audio and video and that use rtsp.
Also, not often but sometimes rtsp tunneling over http is used Reason is that routers are mostly open by default to let http traffic pass. Using rtsp need to open routers manually and if you have many routers to pass this will be a problem.