Purpose, Goal, Motive
noun
When your eye is on the target you know your purpose. You also have your eye on the goal (that's the target, after all!).
もくてき
The reading is a reading for 目 that's abnormal. You've seen this reading with 目標 and 目次, though, so hopefully it won't be too hard at this point. Just imagine telling someone your 目的, only to have them laugh in your face and begin mocking もく you for it. Now you're not so sure if your goal is going to work.
一体、目的は何なんですか？
What the heck is your goal?
学生さんのサポートを目的としたビジネスをしています。
I'm running a business aimed at supporting students.
私たちの目的は、皆さんに楽しく日本語を勉強してもらうことです。
Our goal is for everyone to enjoy studying Japanese.