There are different ways that chainmail is made: Riveting and butting.
Riveting:
Riveted chainmail is highly resistant to cuts, slashes and stabbing. Riveted chainmail is historically used in the medieval times. Butted mail was not used back then, butted mail is merely used for modern day reenactment because it is easier and quicker to make than riveted mail.
Butting:
Butted mail has rings bent together with no mechanical connection, this can result in the mail being more easier to break. Butted mail does provide some protection against slashes and stabs but it is no where near as effective as strong linked riveted mail is.