created

Evaluate the rule criteria each time a record is created. If the rule criteria is met, run the rule. Ignore all updates to existing records.

With this option, the rule never runs more than once per record.

created, and every time it’s edited

Evaluate the rule criteria each time a record is created or updated. If the rule criteria is met, run the rule.
With this option, the rule repeatedly runs every time a record is edited, as long as the record meets the rule criteria.

Note: We cannot add time-dependent actions to the rule if you select this option.

created, and any time it’s edited to subsequently meet criteria

Evaluate the rule criteria each time a record is created or updated.

For a new record, run the rule if the rule criteria is met.

For an updated record, run the rule only if the record is changed from not meeting the rule criteria to meeting the rule criteria.

With this option, the rule can run multiple times per record, but it won’t run when the record edits are unrelated to the rule criteria.

(Or)

If we want to trigger the workflow only when the record is created, we have to use “created”.

If we want to trigger the workflow whenever the record is created or edited even though it has currently met and triggered, we have to use “created, and every time it’s edited”.

If we want to trigger the workflow whenever the record is created or edited and previously it didn’t meet the criteria.