What’s the difference between mustRunAfter and dependsOn in Gradle?

For example:

tasks.create('a')

tasks.create('b').dependsOn('a')

tasks.create('c')

tasks.create('d').mustRunAfter('c')

• dependsOn – sets task dependencies. Executing b here would require that a be executed first.
• mustRunAfter – sets task ordering. Executing d does not require c. But, when both c and d are included, c will execute before d.