Are there two areas where a user can log in?

I have modified my theme. I have added a button to the comments.php so that when the user wants to add a comment and he is required to register or log in, he is given the option to click on a button (It is part of my design and requirements for my specific web design).

Here is my question. Are there, in fact, two areas where a user can log in?

I noticed that if a user clicks on "log in" from the home page, he goes to a page that looks something like this:

http://i67.photobucket.com/albums/h292/Athono/login.jpg

But if he clicks to respond to a blog, he goes to the bottom of the blog like so:

http://i67.photobucket.com/albums/h292/Athono/arguemax2.jpg

One of the places can be modified by the comments.php page, where can the other area be modified?