Convert to Invoice: This feature enables Customer to convert Quotation into Invoice to make a payment.
Remaining features are similar for both Invoices and Quotations. So please go through the Invoice view page for common features of Quotes.
Once the Quote is converted into Invoice, the quotes present in Quotes page are displayed with a tag as Invoiced.
Even the view page for Quote is entitled with a sentence “Quote is converted with Invoice Number xxxx”.