Thank you very much for your question.
The engine management unit (ECU) has detected a fault and this is why the engine management warning light has activated. The most common causes are faulty camshaft or crankshaft sensors, a faulty lambda (oxygen) sensor, or a faulty coil pack or spark plug.
A fault code should be stored on the ecu's memory which will point your garage in the direction of the fault. The only way to find out what has caused the problem is to take your car to a garage that has the correct diagnostic equipment, and have a diagnostic check carried out, which will reveal what the fault code is. Most garages have this equipment nowadays, so I would suggest phoning round for a quote unless you have a regular garage. You do not have to go to a main dealer although their equipment may be able to give a more detailed diagnosis.
There are many reasons why the light could come on, so guessing would not be wise and will almost certainly end up costing you money.
Continuing to drive your car should not be a problem if you take it easy, unless the engine starts to missfire, in which case damage can occur to the catalytic converter. However my recommendation would be to have a diagnostic check carried out as soon as possible, just in case.
I hope this answers your question.