A check mark or tick is a symbol used to indicate the concept "yes".
The check mark is a predominant affirmative symbol of convenience in the English-speaking world because of its instant and facile composition. In other countries, however, the mark is more complicated. In some countries (e.g., Finland, Italy, Japan, Korea, Norway, and Sweden), the check mark can be used as an error mark, indicating "no" rather than "yes". For example, it is common in Swedish schools for a ✓ to indicate that an answer is incorrect.
In China, a check mark means "correct". A check mark placed in brackets can indicate that a previously used or acceptable fact or definition is being investigated, usually for the purpose of expanding academic research.
In Japan, an "O Mark", also known as "丸印" (marujirushi), is used instead of a check mark to mean "yes"; this symbol is also used in Korea and Taiwan.
The "Symbol, Other" category of Unicode provides various check marks:
U+237B ⍻ not check mark
U+2610 ☐ ballot box
U+2611 ☑ ballot box with check
U+2705 ✅ white heavy check mark
U+2713 ✓ check mark
U+2714 ✔ heavy check mark