Invoice Status in Sale Order

In the Sale Order, there is a field named Invoice status.

1) If Sale Order is just created and still in the draft state then the invoice status for that Sale order will be 'Nothing To Invoice'.

2) Once this sale Order is confirmed by clicking on the 'Confirm Order' button from Sal Order the invoice status will be updated from Nothing to Invoice to 'To Invoice'.

3) As the Invoice status is not to invoice there will be a Create Invoice button will be visible in the Sale order and if you create an invoice then the Invoice status will be updated to 'Fully Invoiced'.

NOTE: To create an invoice in a sale order you need a minimum of one sale order line to generate an Invoice otherwise it will throw the warning like there is no invoiceable line existing in the current sale order.