The head part is very important in term of SEO and performances.
Have look at Starter Theme and Classic head part to see real life examples.
PrestaShop 1.7 changed the way asset works and it means the way to it’s added inside the
<head> tag of your page changed a bit too.
There are 2 important files to use:
If you’re using Starter Theme (which I encourage you to do) there is nothing to do, it works out of the box.
Those 2 sub-templates are very simple, they loop and print each provided assets.
A lot of meta and SEO information belong here, there is a special block for it so template which extend this layout can easily redefine the page title or description.