For whatever reason, many people tend to confuse the apostrophe ’ with the symbol ` when writing. Some typical examples are
it`s, don`t, let`s
it’s, don’t, let’s
The use of ` instead of ’ is quite surprising because on an English keyboard, the apostrophe is much easier and faster to type. Using either ’ or ` is not just a matter of taste:
Contractions or possessive forms in the English language are formed using the apostrophe ’. The corresponding key on English keyboards is located to the left of the Enter key:
The symbol ` (the key is located just under the ESC key on English keyboards) is called a grave accent or a backquote. It is used to modify the pronunciation of letters in some languages, and for quotations.
For more details on quotation marks and other symbols, see here.