So, we have TRIM function in Excel. Almost all programming languages provide LTRIM and RTRIM functions also but Excel doesn't provide LTRIM and RTRIM. The same is provided in VBA but most of the Excel users are not using VBA. They are simple folks who want to accomplish their day to day job through Excel functions only.
Before I delve into LTRIM and RTRIM, let's recap TRIM.
TRIM, basically, removes all spaces from your string and if there are more than one space between your words, it will convert them into only one space. So, it removes all leading spaces, all trailing spaces and all spaces between words except one. If there is only one space between words, it will leave that space untouched.