"Such as" is similar to "for example." Example: I like to do many things on the weekend, such as walking, dancing, and singing. This sentence is the same as "I like to do many things on the weekend. For example, I like walking, dancing, and singing." "As" has many more meanings. One meaning is "in the role of." Example: I'm studying English as a beginner. (My role is a beginning student of English.) One meaning is for comparisons. You can use "as" two times, once before the description and once after the description. Example: My face is as red as an apple. (An apple is red, and my face is red. Both are red.) "As" can mean "while" or "at the same time." Example: He laughed as he ran. (He ran. He also laughed. He ran and laughed at the same time.) "As" can also mean "because." This is a kind of fancy style, though, and not as common as using "because." It also is not easy to do without sounding strange. Example: As I don't like meat, I prefer to order salad at restaurants. (Because I don't like meant, I prefer to order salad at restaurants.) Or: I prefer to order salad at restaurants, as I don't like meat. (I prefer to order salad at restaurants, because I don't like meat.) So use "such as" for giving examples. Use "as" for many other things.