You like someone or something, means that you are glad to see man you like, that you love him, or you like a film and you can in any moment watch it. Want express your desire, eagerness. When you see expensive mobile phone in the shop you often say - I want to buy it. When you say I want you to person, you express physical desire, also when you say I want to see you, I want to meet you and so on. This word is widely used in english.