If you don't know what coilovers are then you don't need them. You'll be fine with ordering some H&R or Eibach lowering springs. Shop around on the internet to find a good price.
More like if you don't know what either are you better hold off on getting them until you learn the pro's and con's of both.
If you just blindly get lowering springs you could be looking at blown shocks in months. Or damaging the rest of your suspension because you didn't change your driving habits.
Lowering springs are just springs, that are slightly shorter that OE in most cases. They are usually progressive to make up for the distance meaning they'll usually look like the have uneven spacing between coils while the OE spring will usually have even spacing (there are exceptions for certain cars). What will blow the shock is when the car is lowered, there's a chance the shock will bottom out (the inner valving will hit the tube) or the seals/valves will wear faster because of the different spring rate. Think of a syringe the faster/harder you pull the more it resists this will wear the seals/valves faster. This change can be huge or not noticeable to the shock depending on the spring rate.
Coil overs take care of pretty much all of the above. Most coil overs allow the spring rate and shock to be adjusted to complement each other. In addition the height can also be adjusted (keep this in mind if you live where there's a lot of snow). Because of the adjustability You can raise your car for DD or lower it for tracking. This costs more.
Keep in mind when you lower your car your ride will be "harsher", and you should avoid majour bumps and pot holes because harder springs and shocks will transfer more energy in to the rest of your suspension/car/you.
