Adwords account structure refers to the organization and layout of a Google Adwords account, which is used for managing and running online advertising campaigns. It includes the division of the account into campaigns, ad groups, and keywords, as well as the overall hierarchy and settings within the account. A well-structured Adwords account can help optimize ad performance, increase efficiency, and provide better control over advertising budgets. It is an essential aspect of successful online advertising and requires careful planning and management.