In the context of education:
* Online: This is the most frequent use, especially in the context of online learning or courses.
In the context of business:
* Online: Used to refer to online operations, products, or services.
* Operational: Can indicate something related to daily operations or procedures.
* National: Used to indicate something that is nationwide or national in scope.
Other possible meanings:
* Open Network Labs: A research group focused on open networks.
* Ophthalmic Nursing League: A professional organization for nurses specializing in eye care.
* Ocean Network Line: A shipping company.
To understand the meaning of ONL, you need to consider the context in which it's being used.