In the Settings Administration Screen are all of the settings that define your website as a whole: settings which determine how your site behaves, how you interact with your site, and how the rest of the world interacts with your site.
The Settings General Settings Screen is the default Screen in the Settings Administration Screen and controls some of the most basic configuration settings for your site: your site's title and location, who may register an account at your blog, and how dates and times are calculated and displayed.
Using the Settings Writing Screen, you can control the interface with which you write new posts. These settings control the size of the 'post box' in the Add New Post Screen, the default post Category, and the default Post Format, etc.
The settings in the Settings Reading Screen are few in number, but still important. You can decide if you want posts, or a "static" Page, displayed as your blog's front (main) page. You can also adjust how many posts are displayed on that main page. In addition, you can adjust syndication feed features to determine how the information from your site is sent to a reader's web browser or other applications.
The Settings Discussion Screen allows you to control settings concerning incoming and outgoing comments, pingbacks and trackbacks. You can also control from this Screen the circumstances under which your blog sends you e-mail notifying you about the goings on at your site, and you can decide if your blog should show Avatars and their ratings.
The Settings Media Screen allows you to determine how images, documents, and other media files will be organized when uploaded, and to specify the maximum dimensions in pixels to use when inserting an image into the body of a post.
Next: General Settings