No, nam is a placeholder for whatever is inputed into the function input by the user when the program is ran. Input prints to screen whatever you put () when you first call it. It expects something to then be inputted by the user when the program runs by prompting the user with the message in the (). Whatever the user inputs is then referred to by the variable, in this case "Chuck" was inputted.
It will make a bit more sense when you start writing functions, you can return whatever results you want from calling a function. Those returns will be referred to by the variable you label it, word on the left of the =.
In short, whatever is returned by a function is what is "saved" in the variable.
Mostly their marketing practices. They are designed well but mostly designed to keep you locked in one way or another.
For me, their desktop is not as intuitive as people make it seem and lacks simple shortcuts that most other desktops have.
On mobile, its the restriction of customization and options. They are getting better at customizing but still limit you on options for anything outside of their apps. They claim to be private but follow similar practices as other companies, just in a more quite way with better PR.