SecOps/Security Engineer - Typically focused on responding to security incidents and proactively preventing security issues. Typically this involves threat detection, pen testing, security reviews. They can often reverse-engineer malware but they may or may not be able to write a web app. Probably can't set up the infrastructure to run their security platforms.
DevSecOps - Security focused Devops engineer. Expected to have significant security experience, but probably not doing pen-tests. Likely working on container security, setting up and running security platforms. May be a security consultant for devops engineers the same way a security engineer is a security consultant for app engineers.
Someone who focusses on the security aspects of the code pipeline. There's a lot to do here, which most companies are not. For example, not pulling random containers and packages from the internet, and having a trust path for auditing.