Web archives are repositories of content preserved from the World Wide Web, not to be confused with other types of archives that offer services or content online. Web archives preserve content that otherwise tends to disappear or change rapidly, which probably makes them the most important initiative towards preservation of cultural heritage in our age. Never before have the actions, ongoings, sentiments, trends, decision processes; in politics, business and industry, institutions, news media, entertainment providers, interest groups, and individuals, been documented or preserved at the level of detail offered by ongoing and systematic preservation of the Web, with content from all levels of society. This book strives to present the underlying methods and reasons for preserving web content, with a focus on the principles (rather than specific methods that may become obsolete almost as quickly as web pages may disappear), and on detailing the nature of the archived results with its potentials and pitfalls. Review: The book's strength is in its unique position in the market. Harlung's monograph proudly embraces the 'web archiving for dummies' mindset and turns out to be successful in it. (...) Its strength lies in guiding students and practitioners through that middle ground, demystifying the unfamiliar terrain of web archiving and encouraging steady engagement with its real challenges. This is a great kick-starter into web archiving and provides a smooth transition into more advanced literature, before grabbing one's first Brügger or Milligan off the shelf. - Andrea Kocsis, Internet Histories, December 2025