The difference is whether or not what follows "like" or "such as" is meant to be included in what you're talking about. "Like" says that what follows is intended as a frame of reference to indicate the group of things you're talking about but is itself not included in the group. "Such as" means that what follows are examples of the things that are part of the group you're talking about. "As" is a conjunction, while "such as" and "like" are prepositions. There is difference between sentence structure: verb + like (such as) + noun / pronoun. For example: He speaks like a native speaker. but as + subject + verb. Example of using "as": Nobody sings as she does. Another use of "as" is to say what the role/function of a person/thing is. For example, "He started work as a carpenter".

Ha ha, I can see why it would be confusing! They're very similar, and the differences are only grammar technicalities. I think there wouldn't be any good explanation of what the difference is, you probably just need to get used to it by reading lots of examples. Because the other problem is that each of these words can be used in a few different ways as well. But I'll try... "Such as" and "like" can be used interchangably to give comparisons or examples. "I could give you many examples, such as just yesterday when I ... ", or "like just yesterday when I ..." "Such" can be used for emphasis - "That was such a good movie!" "Such" can used like a pronoun - "Money, fame and such" (which means, and other things like that). As you can see, you could also use "like" in that sentence, but it would have to be part of a phrase "things like that". "Like" is more often used for comparisons. "I want a bike like that one." "His coat was just like hers." What do you think? Did that help?