Add resolution/fps explanation

docs/how-to/video/video-basics.md

@@ -1,2 +1,23 @@
-# Broadcast Video Basics
+# How Video Works
 
+![](https://media.giphy.com/media/PD0bnCo6m21Xy/giphy.gif)
+
+Ever make one of these Post-It note flipbooks to create an animation? You draw each frame by hand, changing it slightly each time so that when you flip through the pages quickly it looks like movement. This is the same principle we've been using to create movies and animations since the 1890s.
+
+Video hasn't changed much since then. The only difference between the flipbook above and the video equipment in our studio is that the flipbook uses paper to show each frame, while our equipment uses a digital display. Instead of a person drawing each frame on a sticky note with a pencil, our camera takes a picture, then sends it over a cable to a screen, and repeats this over and over many times each second. The speed we flip through the book is called **frames per second** or **fps**. Computers operate at 60fps, most movies and TV shows are shot in 25-30fps.
+
+Our studio operates at 60fps, meaning that we "flip the book" 60 times each second.
+
+---
+
+# How We Send Video
+
+Remember that instead of drawing each frame on a sticky note with a pencil, we tell our TV screens how to draw each frame over a cable. The TV follows the instructions we send it to draw our picture, and repeats that at whatever frames-per-second rate we are using.
+
+But TVs don't use pencils and pens to draw pictures. They use tiny colored dots called pixels to draw the picture, like this.
+
+![](http://kemp21stcentury.weebly.com/uploads/1/7/1/4/17142550/finding-dory-pixel-art-pixel-art-lego-8bit-minecraft_orig.png)
+
+In the picture above, there aren't very many pixels. It's only about 40 pixels wide and 30 pixels high. This is the **resolution** of the picture, or how many pixels it has. 30x40 is a very low resolution; using ``length x width`` we can find that there's only 1200 pixels in that picture of Dory. Real broadcast equipment is _much_ higher resolution. Common movie resolutions include ``1280x720``(aka 720p HD), ``1920x1080`` (aka 1080p HD), and even ``3840x2160`` (aka 4K or UltraHD). Our studio operates at ``1920x1080`` resolution, meaning that each frame we produce has over 2 million pixels in it! This is how we can produce high quality images like this using nothing but little colored squares.
+
+![](http://res.cloudinary.com/simpleview/image/upload/crm/huntsville/USSRC-DavidsonCtr032013-4997dKeim0_c10420ce-5056-a36a-08f038dcbd77606f.jpg)