Hi group, I am learning solidity, have a question. I know a bit what is doing this code in general but have line that I can't understand.
struct User {
string name;
string surName;
}
mapping (address => User) private users;


function getUser (address addr) returns(string, string) public view {
User memory user = users[addr];
return (user.name, user.surName);
}
The line is User memory user = users[addr];
user is User type (struct) so how it is comprehensible that I can pass an address key?