OTA enables you to update or reconfigure a device remotely. For businesses with IoT devices in play, OTA has two main uses: firmware updates and SIM profile management.
Firmware updates
Firmware refers to the software within a device that instructs or enables it to perform the functions for which it was created. In other words, firmware tells your device what to do. Over time, you might want to add new improvements or functions to those devices; something that requires the firmware to be altered. You will also need to optimise the code from time to time to address bugs and security vulnerabilities. OTA enables you to do this remotely via the cellular network, without having to recall the devices.
SIM management
A SIM (subscriber identity module) contains the credentials a device needs to connect to a cellular network, and for the network to authenticate that device.
Basic OTA capabilities allow you to provision (i.e. activate and manage) SIM profiles remotely and to update the parameters of the SIM as required. Newer OTA technologies go several steps further. They make it possible to load and manage multiple profiles onto a single SIM, making it much easier to switch between networks.