What is a dHCP?
In one sentence: The helper in your router that lends each device an IP address when it joins the network.
A little more
DHCP is the helper inside your router that hands out addresses. When a phone or laptop joins the network it asks, "who am I?", and DHCP lends it a free IP address plus a few settings it needs, such as which box leads to the internet.
The address is only on loan for a while, called a lease, and the device quietly asks to keep it before the time runs out. Trouble starts when someone types an address into a device by hand that DHCP also lends to another device: two devices with the same address get each other's messages, and you see an "IP address conflict" warning.
See it in action
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