Creating custom networks for better isolation and service discovery.
While the default bridge network is functional, it has limitations, particularly for multi-container applications. The recommended approach is to create user-defined bridge networks using the `docker network create` command. These custom networks offer significant advantages. First, they provide better network isolation. Containers on different user-defined networks cannot communicate with each other unless they are explicitly connected to both, which enhances security. Second, and most importantly, user-defined networks provide automatic service discovery through an internal DNS server. This means containers on the same custom network can communicate with each other using their container names as hostnames. For example, if you have a container named `webapp` and another named `database` on the same network `my-app-net`, the `webapp` container can connect to the database simply by using the hostname `database`. Docker's embedded DNS will resolve `database` to the correct internal IP address of the database container. This eliminates the need to hard-code IP addresses or use legacy linking mechanisms, making your application configuration much cleaner, more portable, and more robust, as container IPs can change when they are restarted.