Free SQL database for website

[Fiamani]

I am new to web development, and I am developing a website. The frontend part of the site is almost complete, but the backend part is not fully done, there are some missing pieces. I need an SQL database for my site as I am working on creating a registration and login system for the site. However, I do not know how to obtain an SQL database for free. Can I find a free SQL database? What are the advantages and disadvantages of a free SQL database? What is the difference with paid ones? I would appreciate it if you could help me with this.