what is the difference between "reservation" and "advance reservation"?
Aren't they both have meaning of 'pre'?
I'm Korean and there's same problem in Korean. But there's no clear answer so I came here
please let me know plz
Whether advance is redundant in advance reservation depends on the context. Usually the phrase stands for a reservation that is made in advance of whatever it is for; when so used, advance in it is indeed redundant. As Anton's answer explains, that may or may not be undesirable.
There may, however, be special contexts in which advance reservation stands for a reservation that is made in advance of the time when the relevant reservations are normally made. In such a context, advance is not redundant.
Your question relates to the use of redundancy in English. You will find your example and many others discussed in:
One way to cut the clutter in our writing is to eliminate repetitious expressions. Because we so often see and hear redundancies (such as "free gifts" and "foreign imports"), they can be easy to overlook. Therefore, when editing our work, we should be on the lookout for needless repetition and be ready to eliminate expressions that add nothing to what's been said.
Now does this mean that repetition must be avoided at all costs, or that good writers never repeat themselves? Certainly not. Careful repetition of key words and sentence structures can help establish clear connections in our writing. In effective rhetorical strategies of repetition, we consider how writers may rely on repetition to emphasize or clarify a central idea.
Our concern here is with eliminating needless repetition — redundant expressions that make writing longer, not better. Following are some of the common redundancies in English. In specific contexts, some of these phrases may serve a purpose. More often, however, the phrases weigh down our writing with unnecessary words. We can eliminate the needless repetition in each case by omitting the word or phrase in parentheses.
(absolutely) essential; (absolutely) necessary; (actual) facts; advance (forward); (advance) planning; (advance) preview; (advance) reservations; ...
ThoughtCo