I'm pretty sure you have not received any "summons". A summons is an old term used mainly in criminal or magistrates’ courts to require someone to attend court to answer an offence. It’s the court’s way of starting a criminal case or compelling attendance.
A money claim is a civil matter, not criminal. It’s used when one person or company wants to recover money from another, such as a debt or alleged breach of contract. It usually starts in the County Court or online through Money Claim Online and can lead to a County Court Judgment (CCJ) if not defended.
In short: a summons drags you into court for an offence, a money claim invites you to defend a debt. One’s criminal, the other’s civil.