Aquila and Prisca are Paul's husband-wife disciple team. You know, his go-to couple for all things godly.
The two first appear in Acts when Paul meets them on his first trip to Corinth. Though the couple is originally from Italy, they were forced out by the Emperor Claudius in 49 CE when he declared that all Jews (even Jewish Christians) had to leave Rome (source, p. 1084). The three of them also have the same job—they're all tentmakers So, Paul works and stays with them in Corinth (Acts 18:1-3). How cozy.
When Paul leaves, Aquila and Prisca tag along on their way to Ephesus. Paul writes his first letter to the Corinthians around this time, and that's probably why he sends greetings from Aquila and Prisca back home to their friends in Corinth. Hey, there were no postcards.
Paul also says the couple has a church in their house (1 Corinthians 16:19), which probably means they were fairly wealthy. If your house is big enough to hold a whole group of Christians, you're doing pretty well for yourself.
The couple is mentioned one more time in Romans where Paul calls them out as two people "who risked their necks for my life" (Romans 16:3). They're like superheroes or something.
Throughout his letters, Paul gives little shout outs to Aquila and Prisca in order to shore up some more support for himself. Like Timothy and Titus, these two can be counted on to help Paul mend his fences around the Roman Empire. He namedrops them quite a bit because they're probably well-known members of the Christian community. It also helps that they have roots in lots of different places that Paul is writing to. Hey, even Paul needs some celebrity endorsements now and then.