As a Verb or Adjective:
1. To notice something with your eyes. English = see.
2. To go and see someone and spend some time with them. English = see, visit.
3. To understand what someone means or to understand why something happens. English = see, understand.
Interactive:
1. Used alone to tell your addressee you understand what they mean. English = 'I see!'
2. Used alone to tell your addressee that they should now be aware that what you said before was right because something has just happened that proves you were right. English = 'You see!'