Computer graphics basically deal with teaching the computer how to see and to analyse the images like the field of Computer Vision. It teaches you about various different concepts like colour theory, how to make visually appealing designs, data visualization and so on. Moreover multimedia also deals with things like video edition, VFX and so on.

Design and analysis of algorithms is a much more complex topic in core computer science, and it deals with designing algorithms with minimum time and space complexity to scale the systems effectively.

Hope I have answered your question. All the best!