The volume of a keyword refers to the number of searches for that keyword in a given time period. There are several tools you can use to find the volume of a keyword:

1. Google Ads Keyword Planner: Google Ads Keyword Planner is a tool that helps businesses create Google Ads campaigns. It also provides data on the search volume for specific keywords. To use it, you’ll need to set up a Google Ads account and enter the keywords you want to research.
2. Ahrefs: Ahrefs is a tool that provides data on keyword search volumes and other SEO metrics. It allows you to see the search volume for specific keywords, as well as the difficulty of ranking for those keywords.
3. SEMrush: SEMrush is a tool that provides data on keyword search volumes and other SEO metrics. It allows you to see the search volume for specific keywords, as well as the difficulty of ranking for those keywords.
4. Keywordtool.io: Keywordtool.io is a tool that generates keyword suggestions based on a specific keyword or phrase. It also provides data on the search volume for those keywords.

By using these tools, you can get a better understanding of the volume of a specific keyword and how it compares to other keywords. This can help you choose the right keywords for your app or website and improve its chances of being discovered by users.