Standard terms and conditions serve as a cost effective way of setting out a businesses statement/policy as to how it goes about its business and avoids the need to have to repeat a lot of information time and time again in any business negotiations or contract.
Standard terms and conditions allow a business to address key areas of concern to them e.g. delivery/completion/timescales, price, payment terms, liability, warranties, guaranties etc.
Standard terms and conditions provide a level of certainty (being an agreement in writing) in relation to the business matter being transacted.