The Intel hex (ihex) generally known as hex file, is a format used to store machine language code in hexadecimal form. It is widely used format to store programs to be transferred to microcontrollers, ROM and EEPROM.
First off, understand that this .hex file is in Intel Hex32 format. This means it can support 32 bit wide address memory devices. But the format is broken up into an upper 16 bits and a lower 16 bits. The upper 16 bits are known as the extended address. Every new line begins with a colon.