Difference between mySQL and SQLite in simple terms - Database Solution

I seen many questions posted but not these two exactly. I also tried reading the Wikipedia definitions but I don't have enough technical understanding to know what it is saying exactly.

I am looking for a database solution where the User of a website can enter customized data into the columns in an Order.tbl and link it to their account in the Account.tbl.

Scenario: I make customized shirts. The user would need to log in to their account and order customized details such as pictures and personalized text which could differ from User to User. It would need to be dynamic in this way versus a static selection of shirts.

The software I use to make the shirts can connect to an MS Access database, SQLite database, mySQL database and a few other flat file databases like Excel and CSV.

Currently my software subscription is with Access and SQLite and was informed that Access would not work in my case because I am using web forms. Which leaves me with SQLite or upgrade to handle mySQL.

The only thing I really understand is that mySQL is more robust than SQLite but I am unsure if I actually need it or not.

Any suggestions for a beginnner?