The Creator has one true name which is represented by the letters YHVH in English. The Hebrew letters are "yud, hei, vav, hei". These four letters are referred to as the tetragrammaton and are a contraction of the Hebrew words for, "was, is, and will be". His true name was only said in the Temple and with the Temple's destruction we lost the correct pronunciation.
In the Tanach (Jewish Bible), there are 72 different 'names' used for The Creator, these aren't actual names though, they're descriptions of Him that are contextual. In daily conversation, most Jews the name 'HaShem' which literally translates to 'The Name' in reference to His true name.
God changed Abram's name to Abraham and Sarai's name to Sarah as a sign of their new identities and the covenant He made with them. It symbolized their transformation and the promises God had for them.
Before God changed his name to Abraham, it was Abram.
You can find it in the book of Genesis. (Gen. 11) God calls upon Abram because he obeys God and will become one of God's favorite people. God tells Abram to do something, and he will do it. He almost sacrifices his own son! Later, God changes Abram's name to Abraham.
God chose Abram because he saw that Abram had faith and would follow Him faithfully.
It was Abraham. This name was given to him because it means 'father of many nations'.
When God covenanted with Abraham regarding his lineage He also told him that no longer would his name be Abram but Abraham. Gen 17:4 As for me, behold, my covenant is with thee, and thou shalt be a father of many nations.Gen 17:5 Neither shall thy name any more be called Abram, but thy name shall be Abraham; for a father of many nations have I made thee.
He changed his name to Abraham and the name means "Father of many nations"
Sarai is the wife of Abram. After Abram made a covenant with GOD, GOD changed his name to Abraham. His wife was no longer Sarai, but Sarah. She is the Mother of nations, not the Bible. For the Bible was not written yet. It would not get its first book for another 500 years or so.
Abram Room's birth name is Room, Abram Matveyevich.
Abram Naroditsky's birth name is Abram Aronovich Naroditsky.
Abram Freydin's birth name is Frejdin, Abram Lvovich.
Abram Kozakov's birth name is Abram Naumovich Kozakov.