'Like' can be used to mean that you enjoy something or to mean 'similar to.' Now 'like' is also often used informally, as the Oxford Advanced Learner's Dictionary explains, to mean that the speaker is 'thinking of what to say next, explaining something, or giving an example of something.' For instance, 'he was, like, so upset.' Or, 'So I thought to myself, like, I'd better make a decision.' For a well-researched and fascinating look at the common usage of 'like' in speech, check out this 2007 piece from the New York Times Magazine.
As an ESL instructor, I have been torn about what to tell students when they use or try to use this expression during Cambridge practice speaking tests. When I'm in the mode of thinking 'like' is a lazy way of speaking and then notice that I use it, I silently reprimand myself for such sloppiness. Other times, I am tongue-tied in class trying to search for a word other than 'like', when I'm giving a definition or an example of how to use a word. I was, therefore, relieved to find that language experts consider 'like' to be an acceptable and even logical expression.