It has various meanings, like for some it means the symbol of faith, and for others it is just the inflated form of Constantinople's Council. The Catholic Church, the Eastern Orthodox Church, and the Oriental Orthodoxy accept it. The not-so-rigid forms of Christianity, like Lutheranism, Protestantism, and Methodism also accept it.
A creed was the best option, as it is an example, an epitome and not a definition, which was essential according to conventional beliefs, so that there was an example for people to look at and put it in their minds as the summary of their faith. So, this was the right solution for those who did not have serious and thorough training in theology and religion.
They could still identify and distinguish between the orthodox and original doctrines, and their deviations, or at times derivatives. Therefore, it was a way to mark what was traditionally Christian and what was not.
So, all the confusions that arose after the Council in 341 AD, and the councils before were resolved by the Nicene Creed, since it was accepted as the penultimate symbol of faith by the defenders of faith and religion.
Different Versions of the Nicene Creed Over the Years
As stated earlier, the original creed was taken up in 325 AD, and the occasion was the First Council of Nicaea. At that, time the conflict was regarding the origin of the creed. The Coptic Church argued that it was authored by the then head of the Church, Athanasius, but then Adolf Harnack said that the Eusebius of Caesarea brought it to the Council.
The creed, however, was changed, and variations were being followed to counter the new phases. Then in the second Council, held in 381 AD, another section was added to the creed, which the Eastern Orthodox Church and the Eastern Catholic Churches now follow.
In the third council that reestablished the version of the second council, it was strictly ordered that whoever tries to change, alter, or write a different creed, would actually go against the faith. Thus, was the concept of Trinity established as the spine of the Christian faith and beliefs!
There are some wings of Christianity who do not recognize the Nicene Creed, like The Church of Jesus Christ and The Church Of New Jerusalem. They reject the creed completely; as a matter of fact, they do not consider it true. In turn, the Nicene Creed itself rejects some of their beliefs as false.