I always find definitions important because all too often I find myself talking at cross purposes with others, because we are actually talking about different things. Part of the problem is that one really needs to clarify the perspective or audience the definition is addressing. For example to a .NET developer, a component might be "an object that implements IComponent", whereas, to a general audience a component might be "something that is a part of a larger system or structure".
Part of the reason this blog regularly posts definitions is to create a handy resource for this author for the precise meaning of IT terminology. Much of the bad writing in tech comes form this misuse of terminology.