Webhooks are user-defined HTTP callbacks, which can be maintained, modified and managed by any third-party users, in order to cause events on one site to invoke behavior on another.
Webhooks can be called from anywhere. They can be added in a VSTS/TFS repo's settings, to extend what VSTS/TFS does when the repository changes (for example, new code is pushed or a pull request is merged).
When the webhook is triggered, the assigned languages/projects on POEditor receive data from the VSTS/TFS file that is connected to it.
In the VSTS integration page, you can find a webhook generator, where you can choose the desired action(s) for your webhook.
Linking multiple files to a language
Webhooks work on a project / language basis. So, if you have several files linked to a language, it's enough to run one webhook with an operation and that operation will be executed for all the files linked to that language.
We strongly recommend that you do not use the sync webhook if you have multiple files linked to the source language. The sync webhook deletes the terms which are in the project, but are not in the connected file. So you may end up losing terms you imported from other files. The terms from the file last synced is what remains in your POEditor project.
Notes: 1) The export option can be triggered from anywhere, except VSTS/TFS.
2) How your webhook behaves is determined by how you set it up in the integration page, in the Settings of each linked language.