'Ils ont' means 'they have' in English. It comes from the French verb 'avoir', meaning 'to have'. An example of this might be 'ils ont un chat noir' - 'they have a black cat'.
'Ils sont' sounds quite similar, but has a different meaning. In English, it means 'they are' and comes from the French verb 'être', meaning 'to be'. Watch out for the circumflex on the 'e'! An example of this might be 'ils sont amicaux' - 'they are friendly'.
Is that clear? Can you come up with an example for each yourself?