what is the @ + number means for task name

Question

I found many task names are end up with @ sign plus a number, please see example below

# Provides credentials for Azure Artifacts feeds and external Maven repositories.
- task: MavenAuthenticate@0
  #inputs:
    #artifactsFeeds: MyFeedInOrg1, MyFeedInOrg2 # Optional
    #mavenServiceConnections: serviceConnection1, serviceConnection2 # Optional

What's the purpuse of this @0 for universal identity?

Answer 1

It represents for task version.

And this configuration corresponds to the task version selection operation from UI:

In your scenario, after the pipeline start to run, it will download MavenAuthenticate task which version is 0.*.