About virtual addresses, linear addresses, logical addresses, and physical address distinctions.

This paper mainly refers to the Linux0.11 kernel of 32-bit address differentiation, but at this stage of the 64-bit address differentiation is not very large, understanding Linux0.11, to help understand the current 64-bit system under the concept of address.
(Note that the x86 system is a small-end storage data)
	
1, virtual address: is generated by the program * * Segment Selector * * and the * * section of the offset address * * two parts.
because these two parts can not directly access the physical memory, after a segmented processing can be possible to correspond to the physical
address (if you open the paging mechanism, you need to go through the paging to correspond to the physics address), virtual
The address consists of a selector (16-bit): An offset value (32-bit) that consists of 48-bit addresses. The first 13 bits of the selector are added to the
GDT and LDT1 bits, so there are 16,384 selectors. The largest virtual address space is: the 16384X4G=64T virtual address space.
	
2, the logical address: refers to the program generated and segment offsets related to the offset part of the address.
in the x86 system is the program execution section within the length of the offset address, is the virtual address to remove the selector of the 16-bit
address of the remaining address is the logical address. An application programmer typically addresses a
logical address, such as the address of the variable you are printing, the address of the pointer, the malloc application memory address, and so on.

3, Linear address: is the virtual address to the middle of the physical address, is the address of the processor addressable space. The
program code produces a logical address, or a cheap address within a paragraph, and a corresponding segment base address becomes
a linear one. If you open the paging mechanism, you also need to pass a paging conversion
to generate the physical address. If you do not open the paging mechanism, the thread address = Physical address.

4, virtual memory: Refers to the computer to show more than the actual memory of a large amount of memory.
It allows more programs to run than the actual memory, which allows many large projects to be implemented in limited resources
, and in Linux0.11 he gives each process 64M of virtual memory. So the logical address range is
: 0x00000000 to 0x04000000.