seed.js code not clear, I have a question

seed.js

'use strict';

var Todo = require('./models/todo.js');

var todos = [
    'Walk Dog',
    'Take out Trash',
    'Study'
];

todos.forEach(function(todo, index){
    Todo.find({'name': todo}, function(err, todos){
        if(!err && !todos.length){
            Todo.create({completed: false, name: todo});
        }
    });
});

I have couple of questions that were not clarified in this video that I wanted to be 100% sure of and not 99.9%.

1. The forEach method used on the todo is the one from AngularJs correct?

2. The second parameter of the callback function in the find method Huston uses the variable todos which in my opinion is really bad to do because it can be extremely confusing with the todos array on top. The second argument of the callback after the err argument is the result of the find method within that foreach loop meaning it is returning one todo at a time and not multiple "todos" so using the plural of todo is also really confusing as it is only returning one at a time. So I guess the question here would be. . . am I wrong about this? That todos second parameter was very confusing even for someone who understands MEAN. Should of just named it todoResult

3. And last but not least is in the if statement he used !todos.length to check if the todo exists. I have never seen someone use that logic to check if an array exists. Can someone elaborate on that little piece of logic and what he is trying to accomplish because from what I understood he is trying to check if the result of the find method does not exist.

if(!err && !todos.length)

Thank you.