What is significance of memory at 0000:7c00 to booting sequence?

Question

Why does bios read at partition\'s boot record at 0000:7c00 ? What is special about that address ? what \':\' doing in referencing an address ?

Answer 1

The simple answer is that 7C00h is 1k (512 bytes for the boot sector plus an additional 512 bytes for possible boot sector use) from the bottom of the original 32k installed memory.

The happy answer is that org 7C00h has become synonymous with boot sector - boot loader programming.