64
A 32 bit processor has 32 bit wide data bus while a 64 bit has 64 bit wide data bus. Address bus may or may not be 32 bit or 64 bit wide in the respective processors. To fully utilise the 64 bit data bus the programs must be written in such a way that they can use 64 bit wide data bus. A 64 bit processor can also act as 32 bit.
It means the processor is able to handle a 32bit wide data at a time.
The data path size for a 64-bit processor is 64 bits. This means it supports memory addresses, integer sizes and data paths that are 8 octets wide.
An address bus (that may be 8, 16 or 32 bits wide) that sends an address to memoryoA data bus (that may be 8, 16 or 32 bits wide) that can send data to memory or receive data from memoryoAn RD (read) and WR (write) line to tell the memory whether it wants to set or get the addressed locationoA clock line that lets a clock pulse sequence the processor
64bit processors have most registers specially the integer registers as 64bit. It can handle 64bit wide internal and external data. All internal and external buses may or may not be 64bit wide. - Neeraj Sharma
The 8086/8088 processor is called a 16 bit processor because its basic architecture is 16 bits wide. Its registers and accumulator are 16 bits wide, and the primary data it manipulates without extra work is 16 bits wide.
The external data bus can be as wide as desired, given the necessary compromises between performance, complexity, and cost. The wider the bus, the faster the theoretical aggregate data transfer rate. In the 8085 and 8088, the external data bus is 8 bits wide; in the 8086, it is 16 bits wide; in the 80386, it is 32 bits wide; and in the modern incarnations of 64 bit processors, it is 64 bits wide.
For the Pentium the front side data bus is 64 bits wide. The back side is 32 bits wide.
The original XT PC computers internal data bus was 8 bits wide and was called the ISA bus or Industry Standard Architecture An improvement to this design was the internal data bus that was 16 bits wide and named EISA or Extended Industry Standard Architecture EISA was the cutting edge design when the Intel 386 processor was introduced.
Also known as the "FSB", connects the memory and all of the other devices on your motherboard to the CPU (processor). You can think of it like a highway that carries the data around "Motherboard City". The speed of the FSB is expressed as a frequency (it's clock speed) in MHz (MegaHertz). One MHz is one million cycles per second. The FSB also has a "width", expressed in bits, such as 16 or 32 bit etc.. The wider it is, the more data can be transferred in one clock cycle. So, for example, a motherboard featuring "266 FSB" means that it's FSB runs at 266MHz and is usually 32 Bits wide. Although with "true" 64 Bit processors becoming widely available, the bit width can be 64 bits wide.
data
In computer architecture, 32-bit integers, memory addresses, or other data units are those that are at most 32 bits (4 octets) wide. Also, 32-bit CPU and ALU architecturesare those that are based on registers, address buses, or data buses of that size. 32-bitis also a term given to a generation of computers in which 32-bit processors were the norm.The range of integer values that can be stored in 32 bits is 0 through 4,294,967,295 or −2,147,483,648 through 2,147,483,647 using two's complement encoding. Hence, a processor with 32-bit memory addresses can directly access 4 GB of byte-addressablememory.The external address and data buses are often wider than 32 bits but both of these are stored and manipulated internally in the processor as 32-bit quantities. For example, the Pentium Pro processor is a 32-bit machine, but the external address bus is 36 bits wide, and the external data bus is 64 bits wide.32-bit - Computers or software programs capable of transferring data 32-bits at a time. Examples of 32-bit operating systems are OS/2 and Windows NT. The first true 32-bit processor was the Intel 80386. 32-bit can also refer to the amount of colours a video card is displaying. 32-bit is the same as 16.7 million colours (24 bit colour with a 8-bit alpha channel).