Handle has several meanings:

1. The part of an object you hold onto. A coffee mug has a handle on its side, a suitcase has a handle on top, and a door has a handle you turn or pull. Handles are designed to make objects easier to grip, carry, or control. Think about how different a frying pan would be without its long handle, or how much harder it would be to carry a bucket without one.
2. To deal with or manage something, especially something difficult. When you handle a problem at school, you work through it instead of avoiding it. A teacher who can handle a noisy classroom knows how to restore order. Someone who handles pressure well stays calm during stressful situations. Parents often talk about how to handle disagreements between siblings. The word suggests capability and control: you're taking charge of the situation rather than letting it overwhelm you.
3. To touch, hold, or move something physically. Museum signs often say, “Please do not handle the artifacts,” because touching old objects can damage them. When you handle something fragile, you need to be careful with it.

The phrase “get a handle on” means to start understanding or controlling something: “I'm finally getting a handle on long division.”