I'm glad you asked about this, Ashraf Obay1.
The Category Details section is based on the accounts in your Chart of Accounts. If the transactions or purchases are directly posted to an account, then choose an account from this section when recording a bill/expense.
On the other hand, you'll use the Items Detail section if you're creating a bill for a specific item/s.
Feel free to ask more questions by leaving a reply. I'll be here to answer them for you.
