Keywords

Keywords are terms or short phrases that represent the topics, concepts, or entities covered by a document or a query. In information retrieval and digital indexing, keywords help connect user questions to relevant content, aiding search, discovery, and categorization across catalogs, knowledge bases, and search engines.

In search engine optimization and content strategy, keyword research identifies terms users are likely to search and gauges their competitive landscape. Content creators incorporate relevant keywords in titles, headings, and body text to signal topic relevance while preserving readability and user intent. Best practices emphasize natural usage and topic coverage rather than high keyword density, and avoid stuffing or manipulative tactics.

Historically, some systems used the HTML meta keywords tag to declare target terms, but major search engines have de-emphasized or ignored it due to abuse. Modern indexing relies on page content, structure, links, user behavior, and semantic signals to infer relevant terms and topics.

Keyword extraction and analysis use algorithms such as TF-IDF, TextRank, and other co-occurrence methods to identify salient terms within text. Keywords are often categorized as short-tail (more general) and long-tail (more specific), and as navigational, informational, or transactional in intent analyses. Tools for keyword discovery and planning include Google Keyword Planner, SEMrush, Ahrefs, and Moz, among others.

Overall, keywords remain a foundational element of information retrieval and content strategy, guiding indexing, discovery, and optimization while evolving with advances in semantics and user intent.