When I came to my new job, there were so many things I didn't know, so I organized the things I had no idea about and only half-understood in a Q&A format.
There is also content I came to understand well while reading books. It would be better to organize it more concretely again, but for the things I had no idea about in the beginning, I just wrote them down and organized the content I gradually came to understand while searching. More detailed explanations are written as separate posts and attached as reference links.

- Cache
- Database
- Git
- Java
- JavaScript
- Json
- Software Management Tool