Original: The word meat is also used by the meat packing industry in a more restrictive sense—the flesh of mammalian species  (pigs, cattle, etc.) raised and prepared for human consumption, to the exclusion of fish and poultry.
Simplified: In the meat processing industry, (in some countries) the word "meat" is to mean only the flesh of mammalian species such as pigs, cattle, etc. but does not include fish, poultry, and eggs.