Original supporting documents for UK Visitor visa-please clarify [closed]

UK visitor visa checklist says provide original documents and a copy of each document.

Does term original applies to every document we need to provide? For example I know we can submit original birth certificate, marriage certificate, passport even bank certificates can get the certified version from bank but what about payslips, employer's letter of confirmation, tour itinerary and all I can provide is printouts of the documents?

For example I work for a leading bank and our HR department is at a different location.They sent me the letter for visa purpose confirming the employment via email.I printed the PDF version of the letter. Payslips I printed from system. So is the letter from my real estate agent confirming I live in my present address was a printout sent to me via email. Is this OK? what do they mean by it has to be original?

It doesn't seem practical to get originals of every document. From what I know the process is VFS will scan the documents on the appointment date and return it then and there to the applicant, but will keep the passport? Therefore if it is anyway going to be scanned and sent by VFS does it matter that some documents are printouts of original because I have no way to getting the originals of them.