I've tried to see the definition, but i still don't get it. What is their difference and when to use it?
Cancel implies the action is rescinded before it implements, possibly consequence-free. It's the word used to bow out gracefully when prompted to confirm an order.
"Cancel our dinner reservation, we have made other plans."
Abort is an emergency procedure to interrupt an action already in progress because continuing would be disastrous.
"Abort the countdown, we'll wait until the weather clears."
"Cancel" imply if an action is not started. "Abort" imply if an action is started and we do not want to do it.
Cancel Dictionary Definition: If something is cancelled, it's been called off. That's usually a bad thing, but if your flight home from Paris gets cancelled due to weather, consider yourself lucky to have another day of vacation!
- Adjective: (of events) no longer planned or scheduled Antonyms: (of events) planned or scheduled
Abort Dictionary Definition: To abort something is to end it. When something is aborted, it's finished. In a movie, you may have seen people on some kind of mission yelling "Abort! Abort!" That means "Stop!" When you abort a plan or activity, you're ending it, usually prematurely. If you abort a dinner, you cancel it in the middle. If the police abort a raid, they stop it after it has already begun. A writer could abort a novel after writing a chapter or two. You can't abort something that hasn't been started: that's more like canceling or postponing.
- Verb: terminate before completion eg: “abort the mission” eg: “abort the process running on my computer”
- Verb: terminate a pregnancy by undergoing an abortion
- Verb: cease development, die, and be aborted
- Noun: the act of terminating a project or procedure before it is completed. eg: “I wasted a year of my life working on an abort” eg: “he sent a short message requesting an abort due to extreme winds in the area”
"Abort", in this sense, likely derives its meaning from the use of the word by NASA when referring to a last-minute cancellation of a space flight, sometimes by means of using a small rocket to lift the personnel capsule away from the main rocket. It implies using extreme (or at least costly) measures to bring the mission to an end.