Sensor’s are objects that have the capacity to measure something (position, temperature, air quality, movement, electricity consumption, etc.). In some cases, they may also have a degree of memory, enabling them to record a certain number of measurements. For example, a sensor attached to a vehicle broadcasts its speed, size and location to other vehicles in the vicinity.
A gateway is a network node that connects two networks using different protocols together. An IoT gateway, aggregates sensor data, translates between sensor protocols, processes sensor data before sending it towards the Internet, and in return, will get other data to send to a presenter.