In agriculture, Internet of Things means using smart devices like sensors and cameras to gather information about crops, soil and weather. This data helps farmers make better decisions about watering, fertilizing, and protecting their plants. By connecting everything to the internet, farmers can monitor their fields remotely and take action quickly when needed, leading to healthier crops and higher yields. This paper analysis the IoT have developed new device for smart agriculture. The first how IoT works and which device are used for smart farming and then application of IoT in agriculture like precision farming, Livestock Monitoring, Alerts and notification, Crop health monitoring, Sprinkler. Then which IoT device used in agriculture. So, the use of IoT in agriculture will be covered in this paper.