Due to globalisation, the terms 1st world n 3rd world has lost its meaning.
These terms are coined during the cold war era.

1st world refers to USA n allies

2nd world is Russia ( cant confirm )

3rd world is the rest.
Now the terms
developed n
developing are used. Even so, the boundaries of these 2 terms have blurred. Thanks to advances in technology acceptance n growth of the Internet n globalisation.