PhD/Doctorate in the UK

How does completing a doctorate work in the UK? I thought it was something you applied for through the University (like an undergrad or a Master's degree) but online it seems to be that you do research by yourself? How does this then become a degree? Also, is there a difference between a phD and a doctorate? I would be looking to complete this in relation to psych/neuroscience if that is needed for an explanation Thank you!

You’re correct the route in is nothing like an undergraduate or Master’s degree. A phd is more theoretical and a doctorate is more applied research. Both give you the title Dr. Entry routes are: i) apply for a research post (in which case, you will usually be paid a small stipend to complete the research), ii) be sponsored by a company (but will need to find a professor who is willing to support your research and will need your research theme/ question approved by a university) or iii) self fund your research (but stipulations above regarding corporate sponsorship still apply).

Thank you so much! That is super helpful!! ☺️☺️

It's not really, it's mostly nonsense! A PhD and a doctorate are exactly the same thing. It is a degree because it is a programme of academic work that has to reach a preset level of assessment decided by a University in order to be given recognition - a PhD.
It differs from an undergraduate degree and a Masters degree because it has no set syllabus, it is not taught. The general requirement of a PhD is that you produce a piece of research that adds to the body of human knowledge (the exact phrase used varies, but that's the gist).
You apply for it in much the same way as a Masters degree (no UCAS), but there may be a few more steps because of the funding process.
Thereafter, PhDs vary quite a lot between Arts/Humanities and Sciences, in part because of the research methods but mainly because of the funding sources. In the sciences, because you often need access to labs and equipment, and because of the nature of the questions that need answering, the work is often done in teams. So an established academic will win some funding (from a Research Council, a charity, a company, a private donor, or some combination), and will then be able to fund a group of research students to help with the research, each student taking on some small part of the whole project as their PhD topic. Psych/neuroscience will work in this way, with the added element of likely NHS tie ins.
In the Arts, there is much less funding, although it comes form many of the same sources as science funding, and research is rarely done in any sort of team, it is an individual topic that you choose before you apply.