# Scripts

*Scripts* are executable entrypoints similar to a `main` function in a conventional language. A script typically calls functions of a published module that perform updates to global storage. Scripts are ephemeral code snippets that are not published in global storage.

A Move source file (or **compilation unit**) may contain multiple modules and scripts. However, publishing a module or executing a script are separate VM operations.

**Syntax**

A script has the following structure:

```rust
script {
    <use>*
    <constants>*
    fun <identifier><[type parameters: constraint]*>([identifier: type]*) <function_body>
}
```

A `script` block must start with all of its `use` declarations, followed by any `constants` and (finally) the main `function` declaration. The main function can have any name (i.e., it need not be called `main`), is the only function in a script block, can have any number of arguments, and must not return a value. Here is an example with each of these components:

```rust
script {
    // Import the debug module published at the named account address std.
    use std::debug;

    const ONE: u64 = 1;

    fun main(x: u64) {
        let sum = x + ONE;
        debug::print(&sum)
    }
}
```

Scripts have very limited power—they cannot declare friends, struct types or access global storage. Their primary purpose is to invoke module functions.