Hi Niamhn,
A Summons is basically a written order instructing an individual to attend court to answer allegations and is usually used when the defendant has not been arrested for that particular offence/s A 'Charge' is also instructing a person to court (must attend in person) and is used when a person had been arrested, so a charge 'could' be seen as more serious. Being sent to court requires sufficient admissible evidence in the case for a prosecution to likely result in a conviction and that is is in the public's interest to prosecute.
A court date will be set and formalised in this case by way of a summons. Sec 4 of Public Order Act, is what's known as a summary only offence and can only be dealt with by the Magistrates Court, including a trial. The first court date is basically to enter your plea and other admin, (depending on plea).
If found guilty and convicted then you should receive notification within one month to attend a police station to have finger prints and other samples taken (if not previously taken for that particular offence).
Seek advice from your instructed solicitor regarding counter- action etc