Difference between Html and Html5
HTML 5 is a change to the HTML specification (previously... HTML 4). It adds new elements (tags), removes old ones and clarifies some technical overheads to simplify matters for developers and browser vendors. The new elements allow you to present pieces of the document as having a more specific allocation than just placement in the page. Aside, Header, Article, Section, Nav etc.
The changes all provide more semantic meaning to the content of a page when the code is viewed by a computer, making it easier to reference areas as well as identify what the code is used for and even easier for machines (like search engines) to infer relevance and priority. Bottom line, you don't really have to change much to move to HTML 5 since you probably weren't using the obsoleted elements anyway.
Best ecommerce platform for startups
WooCommerce is a Wordpress plugin used for building ecommerce websites on the Wordpress platform. A large number of Wordpress themes have the WooCommerce functionality built-in. The plugin provides almost all the features that are available in the other open-sources CMS’ listed here. WooCommerce might work out more user-friendly and cost-effective for smaller businesses as well as for those familiar with Wordpress.