Good question. "General" describes something as applicable to many or most situations. It is usually applied to situations or concepts rather than to objects. So you can't say "a general car", but you can say "the general opinion" (meaning the most commonly held opinion", or "the general situation" (meaning the situation as it exists most of the time). "Ordinary" means that something is normal and has nothing special or distinctive about it. It can mean the same as "general" because you can say "the ordinary situation" and it would mean almost exactly the same. The only subtle difference would be that using "ordinary" would imply that you were noting a difference between this ordinary situation, and some alternative situation. We can use "ordinary" for objects. So "an ordinary car" would be an average quality car with nothing special to notice about it. It is sometimes used in a derogatory fashion, so if a friend asked me what I thought of his car, and I said that "It's pretty ordinary", he would probably be offended. "Generic" is usually a more specialist term meaning that something is a good basic example of what is typical about the class of things being discussed. So if I said that "this movie is a generic example of American horror movies" I would be saying that if you want to know what American horror movies are usually like, this is a good example to look at. We often use the word "generic" to refer to medications that have no brand name, but have the same ingredients and effects as the more expensive branded versions. So I might say, "I'm not going to pay for Nurofen when I can get a generic equivalent for half the price."

1) General: Nonspecific and basic. Nothing special or distinct about it. "He has a general understanding of the subject" (His understanding is basic and not specialized) 2) Ordinary: The person/thing is like many other people/things of the same type. Focuses on similarity. "It was an ordinary day" (It was like many other days or it was expected) 3) Generic: Used for manufactured products (especially processed foods and medicines) that do not have a name brand. There is nothing special about them. They are the most basic type. "I buy generic contact solution. The name brands aren't worth the extra cost" (The contact solution is basic and does not have any extra advertised quality or features)