What is the default value of mysql in mac? In addition, how does mysql port work?

I have a vague concept about how mysql works. I have the following questions: Why did I install mysql when I used php and xampp? Now I use node, npm installed mysql again and connected to the same database. I guess this is because of the mysql port. I only have a vague concept about how mysql works. The following problems exist:

1. Why I installed mysql in php and xampp before, and now I installed mysql again in node and npm. When I connected the database, I connected to the same database. I guess this is because of the mysql port. I only know that the default value is 3306. How many mysql installation directories are in my computer? Where is the path?

2. I used navicat and phpmyadmin to access the same mysql path. How does one work?

3. What is the difference between mac and linux in file management? For example, can I directly refer to the linux system solution when I ask a question?

The above are some of my questions. I hope someone can answer them. I hope I can tell you where the root cause of these questions is, it is better to tell me which documents should be read to find out these problems.

Reply: I have a vague concept about how mysql works. I have the following questions:

1. Why I installed mysql in php and xampp before, and now I installed mysql again in node and npm. When I connected the database, I connected to the same database. I guess this is because of the mysql port. I only know that the default value is 3306. How many mysql installation directories are in my computer? Where is the path?

2. I used navicat and phpmyadmin to access the same mysql path. How does one work?

3. What is the difference between mac and linux in file management? For example, can I directly refer to the linux system solution when I ask a question?

The above are some of my questions. I hope someone can answer them. I hope I can tell you where the root cause of these questions is, it is better to tell me which documents should be read to find out these problems.

The root cause of your problem is that MySQL is a C/S-structured application. You can access any management clients such as navicat and phpmyadmin, as well as your php and node Code, all are just using a mysql client (generally, it is implemented based on libmysql. Of course, the latest php version is implemented through its own mysqlnd)
MySQL is a server program that listens to port 3306 by default. Since xampp is installed, it should be located under/Application/XAMPP.

The kernel of Mac OS x is modified from BSD, which is similar to that of Linux. However, OS X also differs from BSD because of many directory customization, therefore, the Linux solution can be used for reference but cannot be completely copied. You can understand the directory planning of OS X and it will be okay.