What is load in electricity?

Load on an electrical system is the power being drawn from the system. All electrical devices like fridges, heaters and light bulbs have an associated power usage capacity measured in Watts(W). Thus, we have a 60W light bulb. When these devices are all connected to an electricity network their combined power usages is load on the system.

Load can also refer to usage of say a house or factory. Often this will vary over time depending on what devices are turned on inside.

The opposite of load is generation, also measured in Watts. A power plant's generation capacity is so great it is usually measured in Mega Watts (MW) or a million watts. The generation and the load on a system have to be balanced otherwise the system becomes unstable. This can lead to load shedding and blackouts.