what my teachers taught me is that you can use "think about" if it is a long process. like i think about going to university. you can use "think of" if it is a short term. like "i think of you the other day" but obviously people say that there is no rule, i may be wrong.

Green Light: These 2 phrasal verbs mean the same thing. You can almost always use them interchangeably. Sometimes one sounds better than the other, but i don't think there is a rule for it.

- think about: 1- to use your mind for a purpose, for example to find an answer to a problem: She thought deeply about the problem. What are you thinking about? 2- to have a particular idea or opinion about sth/sb: What did you think about the idea? - Well, I like it. She thought him kind and generous. - think of: You think of something before you take a decision, you consider doing something (= contemplate): 'There are so many things to think of before we can decide.' 'She’s thinking of changing her job.'

I think theres no diffrence between both phrases

think of = فكر think about = التفكير