USB Host and OTG, i've gone crazy!

In order to connect a flash drive to your device, you need to connect the flash drive to an OTG cable and then connect the cable to your device.

Host and otg are essentially the same thing.

You have host and client modes.
A USB fish drive / keyboard etc... Are all clients
A USB hub / computer etc.. Are hosts. They manage their clients.
Your phone when connected as a storage device is a client.
Your phone plugged in with an otg cable switches your device to host mode so it can then utilize other clients.

For your purposes treat otg and host mode as the same thing.

The main difference between host mode and otg you will find on xda are for devices that don't have otg support by default.
From my past, the early days of the HTC one x and the nexus 4 did not support USB otg.
While the devices where both capable. The phones themselves could not supply power to connected USB devices.
Developers modified android and the kernels to enable host mode. From there you required an externally powered hub to power the client devices and all worked well.
So the main aspect of OTG(on the go) could not be fulfilled because the phone was not powering the clients which meant you needed an external power source.

Summary:
Host mode - allowing connection of external devices
OTG mode - same as host but is all powered by the device itself

Sent from my Nexus 5 using xda app-developers app

---------- Post added at 02:17 PM ---------- Previous post was at 02:15 PM ----------

Just to clarify your post.
Both host mode and otg can change between host and client.

Sent from my Nexus 5 using xda app-developers app