There are credible sources and non-credible sources.
Differentiating between credible and non-credible sources is a skill that can be learned.
Understanding the difference between websites and online databases is important.
What makes a source credible? (Remember CARRDS)
You do not need to question if database sources are credible. They have been curated and vetted by experts, while it's not always clear who authored or published a website.
What is the difference between searching on the internet and on an online database?