Technically, cloud providers provide an SDK and API to enable access from other applications and systems. Cloud SDKs usually support some runtime and programming language in order to build a cloud application.
To connect our IoT device to a cloud server, we should check the cloud provider services for an IoT platform. Amazon AWS has a cloud service for IoT called AWS IoT. Various IoT platforms can connect and make interactions with AWS IoT. Since AWS has various cloud services, we can make our AWS IoT integrate with other AWS resources. For further information about AWS IoT, you can visit the official website at http://aws.amazon.com/iot.
Next, we will build an ESP32 program to access AWS IoT.