What does colon in job name means when using Gitlab CI pipeline?

Question

Using the following CI pipeline running on GitLab:

stages:
  - build
  - website

default:
  retry: 1
  timeout: 15 minutes

build:website:
  stage: build
  ...
  ...
  ...
  ...

website:dev:
  stage: website
  ...
  ...
  ...

What does the first colon in job name in build:website: and in website:dev: exactly mean?

Is it like we pass the second part after the stage name as a variable to the stage?

Answer 1

Naming of jobs does not really change the behavior of the pipeline in this case. It's just the job name.

However, if you use the same prefix before the : for multiple jobs, it will cause jobs to be grouped in the UI. It still doesn't affect the material function of the pipeline, but it will change how they show up in the UI:

It's a purely cosmetic feature.

Jobs can also be grouped using / as the separator or a space.