Accounts in a Ledger - An Explanation

Accounts in a ledger are similar to baskets or buckets used to segregate similar items when there is a need to separately identify a group of mixed items.

Accounts maintained in a ledger are classified as

personal accounts (relating to persons - customers, suppliers, employees etc.)
Real accounts (relating to assets)
Nominal accounts (relating to incomes, expenses etc.)

How many accounts will be opened in a ledger of a firm?

The number of accounts depends on the detail required. As the firm gets bigger and bigger more number of accounts are necessary to maintain the detail required.

For example, a firm may have an account for travelling expenses. If more detail is required, another firm may maintain an account for local travel, a separate account for travel within the country, and still another account for international travel.