What are the different types of pop-up boxes in JavaScript? Explain their syntax, purpose, and use cases.

In JavaScript, there are several types of pop-up boxes that developers can use to interact with users. The three primary types are:

1. **Alert Box**  
2. **Confirm Box**  
3. **Prompt Box**

### 1. Alert Box

**Purpose:**  
The alert box is used to display a message to the user. It's often used for warnings or important notifications.

**Syntax:**  
```javascript
alert("Your message here");
```

**Use Cases:**  
- Informing users about an action that has been completed (e.g., "Data saved successfully.")
- Warning users about potential issues (e.g., "You have unsaved changes.")
  
**Example:**
```javascript
alert("Welcome to my website!");
```

### 2. Confirm Box

**Purpose:**  
The confirm box is used to present users with a choice between two options: OK and Cancel. It returns a boolean value based on the user's selection.

**Syntax:**  
```javascript
let result = confirm("Are you sure you want to proceed?");
```

**Use Cases:**  
- Asking for user confirmation before performing critical actions (e.g., deleting an item).
- Verifying decisions (e.g., "Are you sure you want to log out?")

**Example:**
```javascript
if (confirm("Do you really want to delete this item?")) {
    // Code to delete the item
    alert("Item deleted!");
} else {
    alert("Deletion canceled.");
}
```

### 3. Prompt Box

**Purpose:**  
The prompt box is used to get input from the user. It displays a message along with a text field for user input, and it returns the input value as a string or null if the user cancels.

**Syntax:**  
```javascript
let userInput = prompt("Please enter your name:", "Default Value");
```

**Use Cases:**  
- Collecting user data, such as names, email addresses, or other input.
- Asking users for specific information to customize their experience.

**Example:**
```javascript
let name = prompt("What's your name?", "Guest");
if (name) {
    alert("Hello, " + name + "!");
} else {
    alert("Hello, Guest!");
}
```

### Summary

- **Alert Box:** Displays a simple message to the user. No user input is required.
- **Confirm Box:** Asks the user for a yes/no confirmation and returns a boolean based on the response.
- **Prompt Box:** Requests user input and returns the input value or null if canceled.

These pop-up boxes are simple and effective ways to interact with users in web applications, though they may disrupt the user experience due to their modal nature. Therefore, they should be used judiciously, especially in modern web development where cleaner user interfaces are preferred.