Developers (Dev), Site Reliability Engineer (SRE), and Operations (Ops) are job types, while DevOps is a system. If we take a soccer analogy, Dev, SRE, and Ops correspond to positions like forward, midfield, and back, while DevOps is a formation like 4-3-3.
Also called Development Engineer, Software Engineer (SWE), Software Developer, or simply Developer (Dev). Their primary responsibility is to write code and implement software business logic. The logic could be fulfilling a grocery order, scheduling a cab to your place, etc. Developers mainly deal with the code.