What exactly is raw and jpeg anyway? Can I still use portrait mode in raw?
The simple answer is that RAW files do not have any in camera processing done to them. JPG's are processed by the camera and if the settings you are using add contrast, saturation, white balance, etc. they will be applied to a JPG but will not be applied to a RAW file. JPG files are also compressed, so you will end up with much smaller files than if you shoot in RAW. My 12 Mp camera outputs 4-6 Mp JPG files, and outputs 10-12 Mp RAW files. So you can see by that, that I have a lot more data to work with in RAW.
The only things that impacts the RAW file is shutter speed, aperture, and ISO. As long as your camera modes are only using those, then yes you can use them in shooting RAW. But if, for example, your camera has a vivid setting, that will not be applied to the RAW file.
The biggest advantage to shooting RAW is that you get to make all the processing decisions on your photos, and you have the most information to work with in the photo in order to do your processing. With JPG, you can be somewhat limited in what you can do to a file in post, but if you are getting it right in the camera to begin with, you may not need to do much.
Editing RAW files can be more labor intensive, but with retaining
all the information the camera captured, you have the most options. I used to shoot RAW exclusively, but have started shooting more JPG lately. If I am shooting a lot, and the shots aren't going to be that important to me, I will shoot JPG. But if I am aiming for more than just snapshots, I will use RAW.