The document you are reading is not a common website but an interactive programming environment called a "notebook". It is a collection of interactive cells that can be freely created and edited. There are two types of cells, code and markdown cells.
Congratulations! You just ran your first little program using Weblab. As you can see, Weblab displays the last expression in a code cell as its output. To learn more about code and markdown cells check out the Getting Started guide.
One advantage of using a notebook to run your code, is that you can immediatly visualize its output. This is particularly handy when you are processing data, for example for a machine learning application. To see how this works we will have a look at an example of the tensorflow project where we use a pre-trained neural network to classify images.
The goal of this example is to classify images that are taken from either the internet or captured by the webcam. Neural networks are great for image classification but their training requires a lot of data and computational effort. Luckily we can skip the training process and use an existing, pre-trained neural network called MobileNet for our classification.