When selecting a keyword research tool, you should consider features such as the ability to filter by country, language, or region; analyze the search volume, competition, and trends of your keywords; generate keyword ideas; and export or integrate your keyword data. Popular tools that offer these features include Google Keyword Planner, SEMrush, and Ahrefs. Google Keyword Planner is a free tool that allows you to find keywords based on your product, service, or website. SEMrush is a paid tool that enables you to find keywords based on your domain, competitor, or topic. Ahrefs is also a paid tool that allows you to find keywords based on your domain, competitor, or keyword. With all of these tools, you can see the estimated monthly searches, competition, bid ranges, search volume, difficulty, trend, clicks, and SERP features for your target market and language. Additionally, they can be used to conduct a comprehensive SEO audit; track rankings; monitor competitors; analyze backlinks; perform a site audit; and research content opportunities.