What kind of pictures should be drawn by a good drawing tool/software?

Process On

https://www.processon.com/diagrams/new#template
There are relatively complete templates related to software development.

What kind of drawings are generally needed for software development?

https://cloud.tencent.com/developer/article/1552210
Mainly use case diagrams, activity diagrams, business module diagrams, class diagrams, and sequence diagrams

A common misunderstanding is to write code directly. In fact, it is more important to draw pictures well so that you can have a clearer and complete understanding of the code structure. Because diagrams can more intuitively display the static and dynamic structure of the code, they are more convenient for system analysis. When encountering problems, it is easier to form clear thinking about complex codes, instead of falling into a sea of ​​specific code logic statements.