Explain the concept of asynchronous task execution and how it differs from the synchronous approach.

Asynchronous task execution means that tasks are started and run independently of the main program thread, allowing other operations not to be blocked. Unlike the synchronous approach, where code execution occurs sequentially and the next step waits for the previous one to finish, asynchrony allows the program to continue working while the task runs in the background.

For example, when loading data from the network synchronously, the application "freezes" until a response is received, whereas in asynchronous mode, loading occurs in parallel, and the user can continue interacting with the interface.

In C#, asynchrony is implemented using the keywords async and await:

async Task<string> DownloadAsync(string url)
{
    using var client = new HttpClient();
    string result = await client.GetStringAsync(url); // does not block the thread
    return result;
}

Here, await allows waiting for the result without blocking, and the method returns control to the calling code, which can perform other tasks.