1. To indicate a footnote or endnote:
*The dog was very *fluffy*.
*The dog was very fluffy.*
2. To mark an omission:
I can't remember the exact date, but it was somewhere around *March 15th*.
3. To highlight a word or phrase:
*Please* be quiet!
4. To represent multiplication in mathematics:
2 * 3 = 6
5. To indicate a placeholder in a computer program:
The file name should be *filename*.txt.
6. In informal writing, to represent emphasis or a pause:
*Wow!* That was amazing!
7. In informal writing, to indicate a missing word:
He was so *angry*!
8. In some cases, it can be used as a symbol for a star.
The sky was filled with *asterisks*.
Remember that the specific meaning of the asterisk will depend on the context.