N.A.T.

IPv4 ADDRESSes built the internet. But they ran out of combos in late 90s 

NAT "network address translation" fixed this

You used to have to be manually assigned a network ID via your internet provider

Downside of this was your network ID was public to hackers = therefore FIREWALL was born

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If someone got past your "Firewall" 

all of the PCs on your WAN & LAN were vulnerable

**NAT fixed this too**

NAT router/gateway will now give private IP addresses to all PCs on a LAN

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Your private IP ADDRESS goes through NAT gateway 

& the gateway camouflages your address as its own LAN address

(Kinda slows things down unfortunately)

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