A person who introduces another individual is commonly referred to as an "introducer." This role can also be described as a "facilitator" in social contexts, especially when the introduction is meant to foster connections or collaborations. In formal settings, the introducer may be called a "host" or "emcee."
introdution by
The person who introduces a speaker is commonly referred to as the "emcee" or "master of ceremonies." Their role is to welcome the audience, provide background information on the speaker, and set the tone for the event.
I am sure they are called a presenter as well because they are (presenting) the programme which is coming on next. Hipprocker.
slave
a slave
everytime he introduces me to a group of people he introduces me as his "Judy", his exwife.
A person from another country is typically called a foreigner or an international person.
Understudy
Cheater
MC or Master of Ceremonies, Ringmaster in a circus, Host (tv show) Commentator (news), etc.
An accomplice. and in some cases the authorities have termed a person a broker when they introduces a party to another party with a belief that the newly associated parties may together commit a crime.
A call originator is the person placing a call to another subscriber on a telephone network.