If you would like to use an adapter for USB devices on your Android smartphone via the Micro USB or the USB Type C port in order to access USB sticks, external USB cameras, memory etc., then you will need OTG for this.
OTG stands for "On the Go" and is a standard for plugging in and using USB devices on micro USB ports.
Unfortunately, not all Android smartphones support USB OTG and therefore you should check whether your smartphone supports this:
There are the following useful app in the Google Play Store:
If you have this installed on your Android smartphone, then this opens and leads you through the OTG test. If this is positive and your device is compatible, then you can connect USB sticks etc. to the Micro USB port of your Android smartphone.
If OTG is not supported, then this nice option is unfortunately denied you.
You now know how to check if OTG devices can be connected to the Android smartphone.