I wonder there is any difference between two words to express
此. What difference, if any, is there?
这 is more colloquial, usually followed by a classifier
此 is more literary, it does not need classifier, and more often followed by a single character word
The classifier after 這 can often be omitted. For example: 這個地方--> 這地方; 這件東西-->這東西.
Since classifiers work with counting words, we can write 這一個地方; 這三件東西.
But we don't usually use counting word with 此
'此一地方' , '此三東西. just sound unnatural.
We usually won't use "此" before certain people or things. But it's fine to use "此人" which means this people. And "此物" for this thing. For myself, I would like to use "此" in writing. Because most time "此" would sound too official. We could see "此" are used more often in news report or some announcements. For example, I always heard "此时此刻" when somebody is making a speech. And others like 此地 此情 此景.