The Basic building blocks of the IoT system are - sensors, processors, gateways, and applications Each of the blocks has its own characteristics to form a dynamic IoT system.

Basic Building Blocks of IoT
Fig. Basic building blocks of the IoT 

Sensors

The sensor is the front end of the IoT system. The main aim of the sensor is to ├žollect data from the environment sensors or give out data to the environment (actuators) from its surrounding (actuators). Senors are identified with a unique IP address therefore they can be easily determined over a large network. Sensors are active in nature because they collect real-time data. They can either work on their own or work by the user depending on their needs. Examples of sensors are gas sensors, water quality sensors, moisture sensors, etc. 

Processors

Processors are the brain of the IoT system. The main function is to process the data captured by the sensors and process them so as to extract valuable data from the enormous amount of raw data collected. Processors mostly work on a real-time basis and can be easily controlled by applications. These are also responsible for securing the data – that is performing encryption and decryption of data. Embedded hardware devices, microcontrollers, etc are the ones that process the data because they have processors attached to them.

Gateways

The main function of the gateway is to route the processed data and send it to the location for proper utilization. Examples of a gateway are LAN. WAN PAN. LAN, WAN, PAN, etc are examples of network gateways.

Applications

Applications are important for the proper utilization of all the data collected. These cloud-based applications are responsible for rendering effective meaning to the data collected. Applications are controlled by users and are a delivery point of particular services. Examples of applications are home automation apps, security systems, industrial control hubs, etc.

Basic Building Blocks of IoT - connectivity
Fig. Basie building blocks of IoT 

From the above figure, we can understand that the information is collected by the sensor and then processed first via connectivity now.it reaches the embedded processing nodes that can be any embedded hardware devices and are processed there as well. It then passes through the connectivity nodes again and reaches the remote cloud-based processing that can be any software and is sent to the application node for the proper utilization of data collected and also for data analysis via big data.