Explain the concept of Modifier in Jetpack Compose and its role in customizing UI components.

In Jetpack Compose, Modifier is an object that describes how a UI element should look, behave, and be positioned. It is applied to components to configure margins, sizes, backgrounds, clicks, and other properties.

Modifier can be viewed as a chain of functions that sequentially modify or augment the behavior of a component.

Example:

Text(
    text = "Hello, world!",
    modifier = Modifier
        .padding(16.dp)
        .background(Color.LightGray)
        .clickable { /* handle click */ }
)

Here, margins, background, and click handler are applied to the text via Modifier.

Thus, Modifier plays a key role in declarative UI description, allowing flexible and concise customization of components.