Every directory has a shorthand name to refer to itself. That special name is the `.' (dot) and it is a map to the inode of the directory.
It is quite useful when you are in a directory and you only have to enter a `.' to refer to where you are, instead of the whole path.
That's why people refer to the `.' as the "current directory". Or "`this' directory".

Using your example:

Code:

/home/rahualux/details/employee_files/.

It would be as saying: "`That' directory" and it doesn't make much sense, since you have to enter the full path already, including the name of the `that' employee_files directory.

In /home/rahualux/details, there can not be two inodes that has the same name, which means, there can NOT be a file named employee_files and a directory employee_files. Therefore, the trailing `/' in /home/rahualux/details/employee_files/ is not necessary.
mv knows that it is a directory.

To summarize the concepts using your example:

Code:

mv /home/rahualux/emp.csv /home/rahualux/details/employee_files

In human terms, it means, move the file emp.csv to employee_files, if employee_files is a directory, that directory gets a file named emp.csv, if employee_files is a file, that's what emp.csv would be called.

Code:

/home/rahualux/*.csv /home/rahualux/details/employee_files

employee_files has to be a directory, since multiple `anything.csv' can not be renamed to be called employee_files, due to the rule I mentioned before of "there can not be two inodes that have the same name, in the same directory"