This tutorial explains on fundamental concepts of IoT - What is IoT and why we need it, main focus of IoT, and various elements in IoT architecture.
Internet of Things refers to network of intelligent devices and systems. The basic elements or building blocks in IoT are Devices with
Sensors
Actuators(collects data)
Gateways (aggregates data in network, stores and communicates with cloud)
Connectivity(which forms network of devices and connects to the cloud)
Cloud(used for storage, analytics, etc.,).