`.DEFAULT` specifies the target that will be executed when we just run make without any target.
`.PHONY` directive, instructs make that it is an explicit target, not connected with any file
More on that: http://www.gnu.org/software/make/manual/html_node/Phony-Targets.html

`V=@` is one way of having the default output of make less verbose. By default if we run
```
echo "Test"
```
as a part of the recipe then the output would be something like
```
echo "Test"
Test
```
To suppress make from printing the command before it is executed we can prefix the command with `@`. To be able to turn it off and on we define a new variable so that when we execute `make` it will use the default value of `V` and suppress the command printing and when we execute `make V=`, then we will see all the commands printed before they are executed.