In subjective point of view, in contrast to Objective Point of View, the reader is told what the characters are thinking and feeling.
You could argue that such a level of intimate eavesdropping is, at least in part, why people read fiction. It’s a level of fly-on-the-wall-ness that they can never, ever get in real life.
No matter how somebody in real life tells them what they’re thinking and feeling, or no matter how somebody relates their thoughts and feelings about an experience in non-fiction - we still know that those thoughts and feelings are filtered and somehow diluted. They come through the clumsy medium of language, and also through the filter of what the person feels comfortable sharing.
In fiction, the language is still clumsy and imperfect … but it is better. You can use language in fiction - poetic or prose language - that would be way too pretentious or formal to use in general conversation.
Also in fiction, because there’s nobody real to be hurt, the character can be made to share all her doubts and vulnerabilities and totally private stuff. And that truly is the nearest we can get to that intimacy with another.
Maybe (I say, only considering this as I’m writing this), that’s a large part of the attraction of fiction, that it provides a respite from our essential existential aloneness … hmmm. Or maybe I’m losing the run of myself and coming over all arty-farty!
Also, this intimacy is part of what necessitates such courage from the writer - because at some level both reader and writer know that there is a real person there … the author, and the author is exposing his own thoughts and feelings in this process.
Anyway, the point is that subjective point of view is the method by which the author allows the reader know the thoughts and feelings of the character. In this POV the author shares what the character is thinking and feeling. So, an example might be:
Do you see how we’re told directly what Betty is feeling (terrified), and thinking (her internal monologue re the umbrella)? But there is also objective point of view in this example: the description of her eyes scanning warily. This is because subjective point of view can fall too easily into the trap of telling instead of showing and the objective description is a needed balance of showing.
You might also have noticed that effectively we shared what Betty was feeling in direct speech. It wasn’t literal direct speech, of course, because it didn’t have inverted commas (quotes) around it - and that’s because it wasn’t speech as such, being her thoughts. But the same principle applies - her thoughts were directly quoted.
Here’s the same scene in indirect speech:
Do you see how that works well too? It’s still subjective point of view, because we are still told what she’s thinking and feeling - but without having to quote her directly.
So ... in balance, the ideal is a good balance of both objective, and subjective, point of view.
Subjective point of view brings intimacy; objective brings better description. Both are valuable, and I truly believe you are well-advised to use both. I've written separate pages because I wanted to make the difference very clear. But in practice, you are best to use both, weaving them seamlessly into your writing.