The goods news is that changing a WordPress theme is one of the easiest things possible. Even if you have no technical background at all, you will still be able to change themes in a matter of a few minutes.
Almost all WordPress themes Generatepress are built in the following manner an index page and single post template that inserts the header sidebar and footer PHP files. Header files usually have some degree of customization to them, linking to the stylesheet, with custom layout elements for the logo or branding elements. Almost all of the sidebar WP3 themes are the same, while the footer php files also have a bit of customization to them. Changing these files can be fairly easy if you know basic HTML. Just make sure to save frequent backups so that you can backtrack one step in case you make a mistake. You can usually make some basic HTML and CSS structural changes to these files without too much effort.
Some WordPress themes make it really easy to customise them and make them your own. When buying a theme you'll want to check what features are included to make your life easy when working on your website.
Notice the 'div' tags that wrap the page elements. HTML is now mainly built with div tags instead of tables. Most div's are assigned a CSS style with a label (selector). Labels can be either an ID (#) more info or a CLASS (.) These styles are defined in another file called style.css. Look through and match the CSS style to the congruent div tag.
So, you have designed your site to reflect you. You have put in a lot of time and effort, and you are quite pleased with the results of your Thesis theme based site. What happens when a new version of Thesis theme hits the streets? Do you have to watch all your hard work vaporize and start building your SEO friendly design again, from scratch? No. No, you don't. That is one, in a long list, of my favorite things about Thesis. Anytime you want to change the style of your site, the underlying HTML code is never altered. This makes Thesis theme the perfect SEO optimized framework for the Wordpress platform. Your code will always be state-of-the-art with every updated version, which are provided to you free.
The Ultimate Blogging Theme gives you an extremely easy option to install any HTML coding at any place of the theme page. This is completely impossible in built-in WordPress themes. This is probably because of the copyright of the themes designed by various designers. So, if you want to add AdSense PPC ads or other monetizing HTML code, you cannot do it on the built-in themes of the WordPress. For that purpose, you will have to download and upload hundreds of plugins, and then you will need to install those plugins, and then you will need to update those plugins every now and then. So, if you want to throw all of this crap out of your mind, just get the "The Ultimate blogging Theme" and make your WordPress theme life easier.