They could be of the same thing however, as some dictionaries mentioned that SEARCH is general and LOOK FOR could be very specific. Meaning you know what you are looking for but you could search for any thing. Hope this help.

You look for mushrooms. You search a place in order to look for something. So you could say: 'I searched the whole forest, but I couldn't find a single mushroom.' the same as 'I was looking for my keys yesterday. I looked everywhere. I searched the whole house, but couldn't find them.' I hope this helps.