why 32 bit means 4 G direct address access

32-bit means that the computer's CPU (central processing unit) can handle and manipulate data in 32-bit chunks at a time. This translates to the CPU being able to handle up to 2^32 memory addresses (4,294,967,296) which is equivalent to 4GB (gigabytes) of RAM (random access memory) directly.

In other words, a 32-bit CPU can access up to 4GB of RAM directly without needing any additional software or hardware. However, if the computer has more than 4GB of RAM, it will need to use additional techniques such as virtual memory to access the excess RAM