Splicing is like splicing cables to add or remove wires. It lets you add new lightning payment channels or make existing ones bigger or smaller without having to stop or interrupt payments.

Dual funding means you can open new channels AND resize existing channels at the same time in one transaction. This saves money on fees compared to doing each one separately.

In the future, dual closing will let you close channels and make normal bitcoin payments in one transaction. Right now you have to do each separately.

This will make using lightning and regular bitcoin payments easier. Users won't have to keep track of separate balances for each. And fees will be lower for payments.

The splicing and dual features mean channels can be added, removed, and resized seamlessly without stopping payments on lightning network. Users won't notice interruptions.

Everything will happen smoothly in the background on the CoreLightning system. Apps on top make payments easy without users having to understand all the complex channel details.

So in summary, splicing lets lightning channels be managed flexibly. And dual funding/closing features make using lightning and bitcoin payments simple and low cost for users.