Template:Isda 6(b) summ
There is a difference between {{{{{1}}}|Termination Event}}s that are non-catastrophic, and usually {{{{{1}}}|Transaction}}-specific, and those that are catastrophic, which are usually counterparty specific.
Non-catastrophic ones affecting just a subset of {{{{{1}}}|Transaction}}s might be caused by, say, a {{{{{1}}}|Tax Event}} or a local {{{{{1}}}|Illegality}}, but in any weather do not concern the solvency, creditworthiness or basic mendacity of your counterparty. They generally won’t have much, directly, to do with your counterparty at all beyond the jurisdictions it inhabits and the laws it is subject to. These are generally the {{{{{1}}}|Termination Event}}s, but not {{{{{1}}}|Additional Termination Event}}s.
The catastrophic ones are by their nature affect — that is, “Affect” — all {{{{{1}}}|Transactions}}. These generally are the bespoke {{{{{1}}}|Additional Termination Event}}s your credit department insisted on — or theirs did; they will have something to do with the naughtiness of lack of fibre of your counterparty (or you!), and these function for most respects a lot more like {{{{{1}}}|Events of Default}}.
Thus, in the drafting of ISDA Schedules, CSAs and so on, you will often find laboured reference to {{{{{1}}}|Events of Default}} and/or {{{{{1}}}|Termination Events}} which lead to {{{{{1}}}|Early Termination Date}}s with respect to all outstanding {{{{{1}}}|Transaction}}s as some kind of special, hyper-exciting, class of {{{{{1}}}|Termination Event}}.
Lucky premium content subscribers get a lot more discussion about the practical implications of all the above and a table comparing the events.