Not important at all!!!
Firstly, it's a 'prima facie case' instead of evidence (note the spelling of 'facie', too). But you don't need to know this phrase for the exam at all, so don't worry.
In a committal hearing the prosecution must prove to the magistrate that they have "enough evidence to support a conviction in a higher court." In other words, the strength of their evidence is such that a jury MIGHT conceivably convict. This is the definition you need to know for the exam.
In traditional Latin terminology this is called a 'prima facie case' - which means a strong enough case to support a conviction 'on the face of it' (because they don't examine the evidence in detail, as the purpose is NOT to prove guilt at this stage). But you do not need the Latin term for the exam, and if you include the Latin term without the English definition you won't get the marks anyway
