The example of enantiomers that I will give here is alpha and beta glucose!
Alpha and beta glucose can’t be more similar in terms of structure, yet one forms the indigestible and tough cellulose while the other forms starch and other yummy goodies like lactose / sucrose.
as you can see from the middle structure, beta and alpha glucose are the one and the same.
The only difference as A level Biology tell us is that the OH on the 1st carbon is above the ring structure for beta glucose but the other way around for alpha glucose.
How to visualise it in 3d? take a look at the image below
can you spot which is the 1st carbon and which is the 4 carbon atom?
Did not you notice whether the OH is above or below?