The VCS feature on central IS is still delivered with 10.3, but deprecated means, there is no further development and it may go away in a future release.
The usual way (just schematic) when doing CI or devops is
Develop on your developmeent server (may be locally or central).
Checkin when ready.
CI server does a checkout (usually automatic), build using ABE (Assets Build Environement) and runs automated tests.
Deployment manager triggers build and deployment to test and eventually production. At least the first time is build anew from the VCS. Wether further test stages and production are deployed from the previous stage or again from VCS differs between different customers.
ABE (Assets Build Environement) is part of deployer, documented in the Deployers Users guide and used to automate building and deployment, usually in conjunction with tools like Jenkins.