The thesis discusses the issues of archiving web content. Firstly, a brief overview of web archiving history is presented, as well as the explanations of common terms within this field (crawlers, types of harvesting, robots.txt files etc.) Legal frameworks of web archiving which include UNESCO’s guidelines on preserving digital heritage and legal deposit laws are also elaborated. The most well-known world organizations, services and tools of web archiving are listed (Internet Archive, Wayback Machine, Heritrix, Archive-It, IIPC, ARC and WARC file formats, WARCreate, Memento etc.) The rapid and wide growth of web archiving initiatives during a span of only four years is discussed. The importance of web archiving for different purposes which can include usage of archived web content in court proceedings is pointed out. Some of the most common technical and social challenges within the complex profession of web archiving (link decay, transferring content, hidden web, removal of content etc.) are analysed. Examples of web archives in Croatia and worldwide (Denmark, the UK, France, and USA) are included, with emphasis on the Croatian web archive. Two different crawlers within the archive are compared. In conclusion, initiatives of archiving the social web in the USA and China are illustrated.