SQL databases are relational databases that use structured query language (SQL) for defining and manipulating the data. On the other hand, NoSQL databases are non-relational and can store and process a wide variety of data models, including key-value, document, columnar, and graph formats. The choice between SQL and NoSQL depends on the specific requirements of your project. PCApps will help you decide based on factors like the type of data you deal with, the scalability required, and the complexity of your queries.