Address binding refers to the process of associating a logical address or symbolic address with a physical address in computer memory. It involves mapping or resolving the logical address space of a program to the physical address space of the computer system. This binding can occur at different stages, such as during compilation, loading, or execution of a program.

Address binding is an essential step in the execution of a program because it ensures that the program's instructions and data are correctly located in memory. It allows the program to access and manipulate data stored in memory by providing the necessary address information.

The different types of address binding include:

1. Compile-time binding: In this type of binding, the addresses of variables and functions are determined and fixed during the compilation phase. The generated machine code contains absolute addresses, which are directly used for accessing memory locations. However, this type of binding restricts the program's flexibility as the addresses cannot be changed at runtime.

2. Load-time binding: Load-time binding occurs when the addresses of variables and functions are determined and assigned when the program is loaded into memory. The compiler generates relocatable code, which contains relative addresses that are adjusted by the loader based on the starting address of the program in memory. This allows the program to be loaded at different memory locations.

3. Execution-time binding: Execution-time binding, also known as dynamic binding, allows the addresses of variables and functions to be determined and assigned during the program's execution. This type of binding is commonly used in systems that support dynamic linking and dynamic loading of modules. The addresses are resolved at runtime using techniques such as symbol tables or dynamic linking libraries.

4. Logical binding: Logical binding involves associating logical addresses, which are independent of the physical memory locations, with physical addresses. This allows the program to be executed in a virtual memory environment, where the logical addresses are translated into physical addresses by the memory management unit (MMU).

Overall, address binding plays a crucial role in the proper execution of a program by ensuring that the program's instructions and data are correctly located in memory. It allows for flexibility in memory allocation and enables the efficient utilization of computer resources.