在路径​​WSUS\更新服务\产品和分类\分类​​,里面有个​​定义更新​​。我不禁疑问这是啥意思?有必要勾选上吗?

pcgeek86表示[1]:"A broadly-released and frequent software update containing additions to a product's definition database. Definition databases are often used to detect objects with specific attributes, such as malicious code, phishing Web sites, or junk e-mail."

我不太明白​​product's definition database​​是啥意思,麻烦知道的朋友在评论区告诉我。是产品自定义数据库的意思吗?

根据pcgeek86的描述,我不禁要问,定义更新和安全更新有何区别?