What is the difference between cat 3 and cat 5?

The difference between Cat 3 and Cat 5 depends on context. In networking cables, Cat 3 is an older twisted pair standard rated for up to 10 Mbps and primarily used for telephone voice, with lower twist rate and more crosstalk, while Cat 5 is a newer standard rated for 100 Mbps Fast Ethernet, with tighter twists, better shielding against interference, and support for higher frequencies up to 100 MHz, Cat 5e is enhanced version supporting 1 Gbps. In tractor hitches, there is no Category 5, hitch categories go up to Category 4 or 5 for very large tractors, but Cat 3 is for 90 to 225 horsepower with 1 7/16 inch pins, while higher categories would be even larger. In hurricane categories, Category 3 is major hurricane with winds 111 to 129 mph causing devastating damage, Category 5 is catastrophic with winds over 157 mph causing total destruction. In water damage, CAT 3 is black water grossly contaminated. So most commonly, Cat 3 vs Cat 5 refers to ethernet cables where Cat 5 is significantly faster and more capable than Cat 3.