Unprocessed
RAW format is a way of storing information about an image so that it gets as close as practically possible to what the camera sensor recorded.
It is not about resolution. The resolution of the image is (unless cropping) determined by the resolution of the sensor. You can have two images in different formats (say JPG and RAW) and they hold the same resolution, but what is different is how much information is stored about each point or dot (pixel) in the image.
RAW format stores much more information about each pixel than other formats do. This maximizes the options for you to work with the image in post processing – you can recover shades in the dark, clipping in the highlights and work with the colors to a degree that no other format allows you to.
But there is no free lunch in photography. The price you pay for all this flexibility and headroom is the file size. RAW format takes up much more space than JPG or HEIC formats, even when the resolution of the image is the same. That is why many edit their images in RAW format and finish their work by exporting the file to a format that takes up less space – this makes sharing on social media much easier.
Related reading
What is a camera image sensor?
What is PASM on your camera body? What are exposure modes?
