HTML 5 and CSS 3 are basic languages, without which today exists in principle any web presentation. Currently, there are in development new versions of these languages, HTML 5 and CSS 3, which gradually begin to be implemented in new versions of most popular browsers. The objective of this thesis is to present an overview of new elements in these languages and the main differences unlike previous versions. Thesis also includes a practical demonstration, in which the new properties are presented. On this practical demonstration was also made the test of support of new elements in four different browsers and results of this test are also part of this thesis.HTML a CSS jsou základní jazyky, bez kterých se dnes neobejde v podstatě žádná webová ...