It is required for record day to day transactions of business and then account is transferred related ledger. So, it is like a primary book of accounts.
Journal is primary book to enter all the data on day to day basis and all the transactions are first recorded in journal whether it is on cash basis or credit, ledger folio basically used to assign the the transaction a no. which can be cross checked from the main or spicfic ledger so that choas and confusion can be minismised.
Jounal is the primmary books of accounts. To record all transactions relate to accounts is recorded in this book, because this is the orginal entry on books of accounts.