Go has two scopes for variables: local and package-level. The main difference between these scopes is their visibility and lifetime.
Local variables are defined within a function or block, and their lifetime is limited to the scope in which they are defined. They cannot be accessed from outside the scope in which they are defined. Local variables are created when a function or block is entered, and they are destroyed when the function or block exits.
Package-level variables, on the other hand, are defined at the package level and have a lifetime that is the same as the lifetime of the program. They are accessible from any file within the same package, and they can be accessed by other packages if they are exported (i.e., their names start with a capital letter). Package-level variables are created when the program starts, and they are destroyed when the program terminates.
Local variables are generally used to store temporary values or to encapsulate data within a specific function or block. Package-level variables are used to store global data that needs to be shared across different functions or blocks within the same package.