Essentially, if you drive a car with an automatic transmission, it’ll change gears for you. If you drive a manual, you’ll have to do it yourself.
Manual cars tend to have three pedals – the clutch, brake and accelerator. The clutch is operated with the left foot. It’s pressed when the driver wants to change gear, which is done with the gearstick. Not all manuals have a clutch pedal – some might have a trigger or button on the gearstick, for instance. But having a clutch pedal is typical.
An automatic, on the other hand, dispenses with the clutch. Instead of a pedal, there’s a footrest where the clutch would otherwise live.
Although there are some variations, the four main operations of the stick are park (P), drive (D), neutral (N) and reverse (R). These are fairly self-explanatory, with the possible exception of neutral, which you use while stopped at lights or in traffic.
Another difference is that you need to use the accelerator to propel a manual car, but an automatic will creep if it’s in drive or reverse. Although it won’t go fast until you press on the accelerator, it will go. This is well worth bearing in mind if you’re used to driving a manual and are planning on making a switch.