The Help Context Tool is used to manage the help context numbers in your project. You can use it to assign, delete, import and export help context numbers in batch mode for your entire project. In addition to this you can also use the tool to automatically generate context help topics from a map file containing a list of topic IDs and context numbers.
Help context numbers are generally only relevant in the Microsoft HTML Help (CHM) format. They are not used natively in any other help format and programmers nowadays generally prefer to use topic IDs instead because they are more "human-readable".
However, if you are already using context numbers for your calls to your help Help+Manual also supports them in URLs for WebHelp. This allows you to use the same context IDs for accessing your web-based documentation as well. See Linking to WebHelp topics for details.