Renaming a directory in MS-DOS is much like renaming a file use the ren or rename command to rename the directory. Because you cannot have a file and directory that have the same name you will not need to worry about mistakenly renaming a file instead of a directory, unless you're using wild characters.
Normal balance is the accounting classification of an account. It is part of double-entry book-keeping technique. An account has either credit (Abbrev. CR) or debit (Abbrev.
This is not to be confused with the average daily balance, which is computed as the sum of daily balances in a billing period divided by the number of days. This is how most checking account balances are measured.