Help with encyrpting my new MY PASSPORT external 2TB drive

I have just bought a my passport external. I as given the chance to encrypt it using bit locker and have accepted. Now it has been enyrpting it for more than 4hrs. I was wandering, how will encrypting affect my external? Does it simply create a password so that I can only access it? or does it cause other complication? Will I be able to use it as if I’m using my pendrive? Thank you

The only thing that comes to my mind is, the backup software might not work properly with a encrypted drive.