Here's what it usually means:
* Emphasis: It's used to highlight a word or phrase, making it stand out from the rest of the text.
* Definition: Sometimes, a word will be boldfaced to indicate that it's being defined later in the text.
* Title: In some cases, boldface is used for titles, headings, or subheadings.
* Key Terms: In academic texts or technical documents, boldface may be used to emphasize key terms or concepts.
Let me know if you have any other questions!