Labels are the display text of various elements of the Help system (output) generated for your end users. For example, the text in previous and next buttons in browse sequences, show/hide and other buttons, tabs, tool tips, and some messages. In PDF outputs, labels are the titles of TOC, index, and glossary pages.
Any text in the output that does not come from your project content is picked from label files. A label file is language-specific and contains labels grouped in various categories such as common, browse sequence, and master page. Each category lists the appropriate labels and its values.
RoboHelp adds a label file in the default language, which is the same as your project language. You can edit the default language file to customize labels in the default language. To customize labels in a language of your choice, you can add, import, or export a label file and then edit it. For example, you can change the default text “Search” on the Search tab to “Find” in a language of your choice.