What does 32 bit and 64 bit mean?

With a 64 bit os you can use more ram, but sometimes the are less stable (windows xp 64 bit) or not compatible with very much stuff (Windows 7 64 bit) basicaly if you are using the computer at your house just go with 32 bit, unless you do a lot of mapping/ compiling / video editing.

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 architectures are those that are based on registers, address buses, or data buses of that size. 32-bit is 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-addressable memory.
In computer architecture, 64-bit integers, memory addresses, or other data units are those that are at most 64 bits (8 octets) wide. Also, 64-bit CPU and ALU architectures are those that are based on registers, address buses, or data buses of that size. 64-bit is also a term given to a generation of computers in which 64-bit processors were the norm. 64-bit CPUs have existed in supercomputers since the 1970s (Cray-1, 1975; CDC 6000 series, 1964, were 60-bit) and in RISC-based workstations and servers since the early 1990s. In 2003 they were introduced to the (previously 32-bit) mainstream personal computer arena, in the form of the x86-64 and 64-bit PowerPC processor architectures. Without further qualification, a 64-bit computer architecture generally has integer and addressing registers that are 64 bits wide, allowing direct support for 64-bit data types and addresses. However, a CPU might have external data buses or address buses with different sizes than the registers, even larger (the 32-bit Pentium had a 64-bit data bus, for instance). The term may also refer to the size of low-level data types, such as 64-bit floating-point numbers.

(Source: Wikipedia)

CPU architectures that based on 32 or 64 integer-long registers, address buses, or data buses.

With 32 bit OS you can use ram up to 4gb but if you get a 64 bit OS you can use over 4gb of ram.

Better operating system. Dude are you a geek or not? 64-bit goes further then galaxy!

half-answer:

X64 pro: -can handle more then ~3.25 GB of RAM; -the software writen in 64bit architecture will run faster (not necesarely 2 times faster then the 32bit).

con: -some apps (mostly on 32bit(X86) architecture) wont function correctly, the X64 system handles the binary code (ex:"011011100110") a little different then the 32bit(X86).

In layman's terms, 32bit gives you 32 lanes of a road, while 64 gives you 64 lanes.

Which is better? Well, it depends on your computer. I will never run a 32 bit OS natively on my laptop ever again. If you're using Linux, go 64. If you're using Adobe Flash or something else that was originally made for a 32bit OS, go with 32. Most 64 bit computers can run 32bit OSes just fine. Not vice versa.

Are you serious?..... wow.....................................