Hi! Doing a PhD is kind of a cross between a university course and a job. It basically means I do a big research project where I learn lots of new things, but also do a new piece of research or experiment which has never been done before. This takes 3-4 years!! I get paid and work full -time hours like you would for lots of other jobs.
To get the PhD I had to do an application process a bit like you would for a job. I had to make a CV ( a list of what qualifications, work experience and skills you have) and fill in a big application form. Then the people giving me the PhD place looked at my application and decided to interview me. I did an interview which was about 45 minutes long, and then a few weeks later they offered me the PhD position.
Once I finish the big project, I will write up all the results from the experiments into a big book called a thesis, and then I have an exam called a viva where other expert researchers will ask me lots of questions about my thesis. A viva can take several hours! Once I have done this, I will graduate university with a PhD, which means I get to use the title Dr instead of Ms. This is because PhD stands for Doctor of Philosophy.