Merriam Webster says that extroversion is "the act, state, or habit of being predominantly concerned with and obtaining gratification from what is outside the self" but Oxford Dictionary says that extroversion means "The quality of being outgoing and socially confident."
Does it also means talkative?
Also is there a difference between the two words?
I think "Outgoing" refers to the behaviour, while "Extroverted" refers to the personality trait (the opposite of "Introverted" in eg. the Myers-Briggs test)
So MW goes on to define an "extrovert" (noun) as "a gregarious and unreserved person", for which "extroverted" is the adjective.
I think in practice, you are right to say that they do get used interchangeably. A person could be outgoing or extroverted meaning their behaviour or personality is socially confident. Hope that helps!
'Extroversion' is a psychological term as you have found it defined by Merriam Webster, which has become sufficiently well-known that 'extrovert' is often used in ordinary conversation to describe a confident, outgoing person.
Obviously such a person is likely to talk freely, but that isn't what the word means. A less socially confident person might also talk a lot to hide their embarrassment.
