Some electric fireplaces insert an infrared heater inside, while others use a fan forced heater, which is used to bring in cooler air and force it over the heating element, as well as pushing the heated air out into the room. It will be sufficient enough to move the hot air around the room and don’t need an additional blower to be able to spread the heat further.
The blower works just like any normal fan and sucks in air from the back of the fireplace and forces it back out through the front via the heating element, which in turn heats up the air as it makes its way out of the fireplace.
Electric fireplaces with fan forced heaters can typically heat areas up to 400sqft, and so if you’re looking to buy an electric fireplace ensure that the heater on an electric fireplace is adequate for the area you’re intending to heat.