In plain terms, DevSecOps means checking software for security problems continuously while it is being built, instead of saving all the checks for the end. It treats security as everyone’s job, supported by automated tools that do most of the checking.
Think of building a house. The old approach was to build the whole house and then call in an inspector, who might find a wiring problem that means tearing out finished walls. DevSecOps is closer to having checks happen as each stage goes up, so a wiring mistake is caught before the drywall covers it.
In software, those checks are tools that scan code as developers write it, test the open source libraries they use, and review cloud settings before anything goes live. When a tool finds a problem, it goes to the person who can fix it, with instructions. The result is software that ships quickly and with fewer security surprises later.