The document discusses analyzing website log files to gain insights for search engine optimization (SEO). Log files record all website requests, including from search bots, and can be used to analyze crawling behavior, error rates, and other metrics to identify SEO opportunities like pages not being crawled frequently or returning errors. Various tools are described that can help with log file analysis, from command line utilities to dedicated log analyzers and SEO crawlers that integrate log data. Key questions are provided that log files can help answer regarding search bot access, crawl budgets, redirect issues, and mobile indexing.