Configuring a service hook in Azure DevOps for Jenkins CI you have to choose an action — Trigger generic build or Trigger Git build.

Which one to choose?

Trigger generic build

This one forces you to choose a build. For a multibranch pipeline, it would be a combination of Jenkins job and branch, like <job-name>/master.

This is ok for freestyle job with only one branch for CI.

Trigger Git build

If you are making CI for features, fixes and pull-requests this action is recommended one. Jenkins Git plugin with ‘Discover branches’ behaviour in a job takes care of the rest.

It’s enough to make a single service hook with this action for all repositories in a project.