Differences between common and static methods in Java

Static methods can be called directly by class names, while common methods can be called only after class objects are created!
Static methods and variables are called to generate a unique identifier in the memory. You can think of it as giving a static location in the physical memory, which can be directly found during the call, it also saves memory, but if you declare too many static resources, then every one will have a seat in the memory, then you will not have the resources to run anything else, and will report a memory overflow!
The general method is controlled by the GC mechanism of Java. during the use of the same object or variable, the time occupies a seat in the memory, the last time has not been deleted from the memory, so there may be two identical items in the memory. These two items are only the same content value, but the memory value is different, you can use "=" and "equals" (this applies only to objects and string types ). java's GC mechanism will automatically clear some unused variables or objects based on the memory status at runtime, even if you manually call GC!