Your electricity consumption or production, as well as your gas consumption, is continuous, but at variable intensity. You do not consume or produce the same amount at all times. For example, when preparing your meals, you consume more because of the high power required by your hob or oven.
Your smart meter registers the amount of electricity and the amount of gas for each quarter of an hour. It therefore keeps a list which, for each 15-minute or 60-minute interval, indicates the average power consumption or generation that has taken place during that interval. This list of values is referred to as the “load curve”.