Unique numerical identifiers assigned to devices on a network, enabling them to find and communicate with each other. Like street addresses for your devices — they tell the internet where to send information. IP addresses come in two versions (IPv4 and IPv6), can be public or private, and can be static (permanent) or dynamic (temporary).
When you connect to your home WiFi network, your phone gets a private IP address like 192.168.1.100 for communicating with devices at home, while your public IP address identifies your entire home network to services on the internet. A web server needs a static public IP address so people can always reach it, while a visitor's phone can use a dynamic address since it changes each time they connect.
All major clouds assign private IPs to resources inside virtual networks (VPC/VNet/VCN) and optionally provide public IPs for internet reachability. AWS Elastic IP, Azure Public IP (Static), GCP static external IP, and OCI Reserved Public IP are comparable ways to keep a stable public address.