Stack Exchange SEO technique
Stack Exchange uses the following URL format for questions:

    +-----------------------------------+-------+----------------------------+
    |                                   |   ID  |                            |
    +-----------------------------------+-------+----------------------------+
    | http://stackoverflow.com/questions/1234567/question-heading            |
    +------------------------------------------------------------------------+
    | http://stackoverflow.com/users    /1234567/user-name                   |
    +------------------------------------------------------------------------+


Though the question loads without the question heading, ie. `http://stackoverflow.com/questions/1234567`, then why does Stack Exchange use the `question-heading` and `user-name` part of the URL?

WordPress too uses a similar URL redressing.

Is this an SEO trick or some other thing?
Stack Exchange SEO technique
===

Stack Exchange uses the following URL format for questions:

    +-----------------------------------+-------+----------------------------+
    |                                   |   ID  |                            |
    +-----------------------------------+-------+----------------------------+
    | http://stackoverflow.com/questions/1234567/question-heading            |
    +------------------------------------------------------------------------+
    | http://stackoverflow.com/users    /1234567/user-name                   |
    +------------------------------------------------------------------------+


Though the question loads without the question heading, ie. `http://stackoverflow.com/questions/1234567`, then why does Stack Exchange use the `question-heading` and `user-name` part of the URL?

WordPress too uses a similar URL redressing.

Is this an SEO trick or some other thing?