Different people will give you different answers, and the answer depends on who is asking and for what purpose!
Motoring offences are criminal offences as opposed to civil. They are dealt with in the criminal courts and are prosecuted by the Crown Prosecution Service. They have nothing to do with the Civil court system.
Fixed penalties are not convictions at all. They are an acceptance that wrongdoing has taken place and an agreement to pay a fixed sum (and possibly penalty points) � less than the going rate if you were fined in court. In return court proceedings (and a criminal conviction) are avoided.
As for recording � all convictions and fixed penalties are held on the PNC. How long they are held for before being deleted (if ever) depends on the offence. Whether they must be declared again depends on the circumstances. Motoring offences � whether dealt with by fixed penalty or as a result of a court conviction � must be declared for varying lengths of time after they occurred.
Some employers do not ask for motoring convictions to be declared, others only if a ban has been imposed � the variations are numerous.