Sofia is the Spanish, Italian, and Portuguese form of Sophia — both meaning "wisdom" from the Greek σοφία. The two spellings are essentially the same name, with Sofia being more common in Romance-language countries and Sophia in English-speaking ones.
Sofia has overtaken Sophia in popularity in many countries — Spain, Italy, Mexico, Argentina, Russia. In the United States, Sofia has been in the top 25 since 2008 and continues to climb.
In Pythagorean numerology the letters of Sofia reduce to 5, The Seeker. This is a traditional interpretive system, not a factual claim about the name.