Yes. It makes a HUGE difference.
JPEG is "lossy." Every time you save a JPEG, the file is compressed in a way that permanently and irrevocably degrades the quality of the image.
RAW files allow more editing. You can change the exposure, the color balance, and more. JPEG, you get what you get. The JPEG file has less information than the RAW file, and you sacrifice editing options.
JPEG degradation is cumulative. If you open a JPEG, edit it, and save it, you get additional degradation. Open it, edit it, save it again, you get still more degradation.
Generally speaking: The JPEG standard was deliberately created for situations where file size on disk is critically important but the quality of the image is not important. If you understand that, you can adjust your workflow accordingly.
