You do web download (text string, files, stream...) with HttpWebRequest, or WebClient, or latest technology HttpClient. If you google each one of them, you could find lots of code samples for downloading.
If the size of downloading is not big, using WebClinet would be easiest, here is the code sample that download the image as you posted:
using System;
using System.Drawing;
using System.IO;
using System.Net;
namespace DownloadFromTheNet
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("Press Enter key to continue, Q to quit...");
var pressed = Console.ReadLine();
if (!pressed.ToUpper().StartsWith("Q"))
{
DoDownload();
}
}
private static void DoDownload()
{
var imageUrl =
"https://maps.googleapis.com/maps/api/staticmap?center=-22.87392394,-42.44314953&size=512x512&scale=1&zoom=20&format=jpg&maptype=satellite&key=AIzaSyAwGppNDUVLYkcHP6_8gUrbzHlNyu4B6NU";
var filename = @"C:\Temp\MyDownloadPicture.jpg";
using (var client = new WebClient())
{
Stream stream = client.OpenRead(imageUrl);
var bitmap = new Bitmap(stream);
if (bitmap != null)
{
if (File.Exists(filename)) File.Delete(filename);
bitmap.Save(filename, System.Drawing.Imaging.ImageFormat.Jpeg);
}
stream.Flush();
stream.Close();
}
}
}
}
HTH