Invoice status - starts in draft mode then is approved (is there any point to draft mode anymore?).
You can issue a quote or invoice by:
emailing it to your customer:
quotes allow customers to accept the quote and add comments via the emailed link: ***link to customer acceptance of quote
invoices allow customers to pay via the link provided you have Customer Payments (link) setup.
Downloading the quote as a PDF.
Printing the quote.
There are a number of options for document layout in settings and you can also choose to customise a quote or invoice at the point of issuing it.
*screenshot customise quote