The camera is continously recording, but you can divide the recordings into more manageable 5, 10 or 15 minute pieces. I set my camera to record 15 minute parts, so after the 15 minute recording is done, it continues to record to a new 15 minute file (some cameras have three second delay in between these recordings. You basically can't have a footage of that three seconds).
It has a micro SD slot. You must insert a memory card, it has no built in memory. The maximum capacity is 32 GB . I have 16 GB Class IV card and at high definition, it canrecord upto four hours.
It also records the sounds inside the car. Although it may be bad for privacy, you can say "I honk the car to warn the driver". I try not to talk about my mother in law when I am driving and the thingie is recoding
Although it has a night vision property (the IR LEDs around the lens), it relies on the lights of your car. It is recording as good as your lights light output.
One thing I noticed is, since it has a wide angle lens, on the footage, it looks like you are speeding. Maybe you remember, a while ago I had an accident in the parking lot and everyone who watched that movie said I was speeding in the parking lot. In reality I was drivingat 20 30 km/h. Some cameras have built in GPS and they show your speed as a watermark on the recording, just like the date and time. It is a double ended sword though...