What do computer scientists actually do?

We’re very specialized kinds of mathematicians, sometimes. In other languages the term is often “Information Science” and in German, IIRC, it’s “Infomathics”, both arguably better names.

Theoretical Computer Scientists write mathematical proofs showing the limits of how information can be stored, transmitted, permuted, hidden, and extracted. Practicing Computer Scientist learn the current best ways to do the above and write implementations thereof. Examples:

Storage: Compression algorithms like zip files, jpeg, mp3

Transmitted: protocols like FTP, HTTP, and yes, ActivityPub

Permuted: A lot of sound editing is done by turning an array of of pitches over time into an array of frequencies over time, changing those frequencies, then turning them back.

Hidden: Encryption, obviously, but also steganography

Extracted: Decryption, obviously, but also natural speech processing and image recognition

They write wikipedia articles that you can quote but do not read 😉

They develop protocols that computers use to communicate. Develop RFC to create industry standards.

They just figure out how to make computers do novel things

Computer Science is basically just a Frankenstein amalgamation of interconnected subjects related to computers that have been useful for universities to lump together for teaching and/or funding purposes. I have a Bachelor’s degree in it. Most of the courses were split between either more “theoretical” / math-y courses on discrete math, probability, “Theory of Computation”, etc. (where we were mostly solving math problems/writing proofs) or practical programming courses on things like “Intro to Java”, “Debugging”, and “Software Engineering Best Practices”, etc. (where we were mostly writing programs). Some met in the middle – e.g. Algorithms, which got into things like graph theory and complexity classes while also requiring us to write programs. The traditional “hard” courses also included compilers and operating systems where we were supposed to learn enough to build at least toy versions of both. I also had digital logic courses that got into to the boundary between programming and electrical engineering (but without going too deeply into how electronics physically works or is manufactured) – e.g. covering logic gates, state machines, the design (but not physical implementation) of CPUs, Verilog, etc.

Basically a “computer scientist” is someone who does something academically interesting about/with computers – either on the mathematics of what can be computed, or on the practical applications of computer technology. Most people who study it go on to become professional programmers rather than academics though.

They like to annoy future programmers by letting them do binariy tree insertion steps manually on paper.
They also like to destroy your self confidence by telling you if you ever come up with an algorithm it is likely trash and someone else inveted a better one 50 years ago.

I have a friend with a doctorate in computer science. He writes accountancy software for a living.

🤷‍♂️

Although his thesis was on designing hardware to function under a different set of physical laws.

Write software that is actually efficient

A lot of very different things. A degree in computer science basically just means you work with computers. I was a CompSci major in college with a specialization in Networking, which means I mostly dealt with stuff regarding networks: running cables, setting up subnets, getting Mac to play nicely with literally any other kind of OS on a network, setting up switches, making wall jacks for Ethernet, etc etc.
Programmers are also CompSci majors (typically). I think game development still falls under it, broadly? I know it did when I was in college.
It’s like asking “What do mathematicians do?” The answer is math, like how the compsci answer is “Computers”

They write code but instead of a company, a university pays them.

/boggle