RCS iOS to Android long distance?

[Confusion1am]

For as long as I can remember imsg was exclusive to Apple and if u wanted to txt internationally the person on the other end would have to have an iPhone as well so that you could communicate through iMessage without racking up long distance charges.
Is RCS the same thing between iOS and android devices? or is there still gonna be extra long distance charges?

Because I turned off my cellular data on my cell phone and I’m strictly connected to Wi-Fi and I’m still messaging through RCS and they’re going through no problem.

I’m just trying to make sure I’m not gonna rack up my bill unknowingly.

***Edited Labels***

[LordDrakkon]

RCS is similar. Hiwever, Apple refused to implent Google's encryption so messages between iOS amd Android through RCS are not encrypted.

Not all countries have implemwnted RCS for Apple devices as of yet and the iPhone user also needs to have RCS enabled on their device once their country/region supports it. Australia is a good example as Telstra is trying to delay doing so as long as possible because they make a lot of money on international messaging charges.