Describe the defer statement in Go and its role in resource management.

In Go, the `defer` statement is a unique construct that allows you to schedule a function call to be executed when the surrounding function or block of code completes. The `defer` statement is often used for resource management, ensuring that resources are properly released and cleaned up regardless of how the function or block of code exits (whether it returns normally, panics, or encounters an error).

The `defer` statement is executed in a last-in, first-out (LIFO) order. This means that the most recently deferred function call will be executed first, followed by the others in reverse order. This behavior ensures that resource cleanup operations are performed in the reverse order of their acquisition, which is often the desired behavior for proper resource management.

The syntax for using `defer` is simple. You place the keyword `defer` before a function call, followed by the function or method call itself. Here's an example:

```
go`package main

import "fmt"

func main() {
defer fmt.Println("Cleanup: Closing File")

// Perform some operations

defer fmt.Println("Cleanup: Releasing Resources")

// Perform some more operations

fmt.Println("Main function execution")
}`
```
In the above example, two `defer` statements are used to schedule the cleanup functions to be executed at the end of the `main()` function. Regardless of the execution path or whether an error occurs, the cleanup functions will always be called before the `main()` function returns.

The `defer` statement is particularly useful for resource management tasks such as closing files, releasing database connections, unlocking mutexes, or any other operation that needs to be performed reliably upon function exit. By deferring the execution of these cleanup operations, you can ensure that they are always executed, even in the presence of early returns or error conditions.

The `defer` statement also helps improve code readability and maintainability. By placing the cleanup operations immediately after the resource acquisition code, it becomes clear and explicit how resources are managed within a function or block of code.

It's important to note that the values used in a deferred function call are evaluated at the time the `defer` statement is encountered, not when the deferred function is executed. This can sometimes lead to unexpected behavior if the deferred function relies on mutable variables that change their value between the `defer` statement and the actual execution of the deferred function.

In summary, the `defer` statement in Go is a powerful mechanism for resource management. It allows you to schedule function calls to be executed when a surrounding function or block of code completes, ensuring that cleanup operations are always performed, regardless of the control flow or error conditions. By using `defer`, you can write more robust and readable code that properly manages resources and avoids resource leaks.