LOVE relates to the feelings of the heart - for example... you love your wife...you married her, you feel strongly about her...you love her so you would say "I love you" to her.
LIKE relates to friendship or enjoyment or good things...for example, I like chocolate chip cookies, I like horseriding...You are a good student/friend of mine, "I like you".
LOVE = strong feeling
LIKE = weaker feeling
Nowadays, people can use either of them when talking with their friends...this is EXAGGERATION. They really really LIKE their friends - so they say "I LOVE YOU"! :)