Database for Mobile applications

I would like build a mobile application in order to learn the technology.

I have chosen Ionic framework for the same, as it takes care of majority of settings for building the application. But, when coming to database for the app which I am trying to build, I am bit confused.

Some links as a result of googling suggest me to use SQLite and some pull me towards Firebase. My doubt is, are they related for comparison? I guess, SQLite and Firebase cannot be compared with. Please clarify.

Thanks Manikandan J