A **decision** represents a point where a behavior needs to choose the best **outcome** from any number of possible outcomes.

The first outcome to satisfy all of its **conditions** is chosen. For this reason, the order of outcomes within a decision is very important.

Conditions are criteria like the time of day, day of week, or the comparison of any record field against some **value** using an **operator** (e.g. is, is not, greater/less than, between, contains, matches, starts with).

Here’s a simple *binary* (two outcome) decision:

- Is it Friday?
- Yes
- No

The *“Yes”* outcome has a single condition that the current day is *“Friday”*.

The *“No”* outcome, being last, doesn’t need any conditions because it would be selected on any day other than Friday. We call this a **default** (or *“catch-all”*) outcome.

This is comparable to an ** if...else** conditional statement in computer programming.

A slightly more complex variation is:

- Day of week:
- Monday
- Tuesday
- Wednesday
- Thursday
- Friday
- Saturday
- Sunday

Similar to the *“Yes”* example above, each outcome would compare the current day against a specific target day, and the behavior would continue down the path (branch) of the outcome that matched the current day.

This is comparable to a ** switch** statement in computer programming.

While the above examples have a single condition for each outcome out of simplicity, an outcome can have any number conditions, optionally grouped into sets with an *any* or *all* constraint.

As you would expect, a set of *any* conditions need only satisfy one of them. A set of *all* conditions must satisfy all of them.

Decisions can also be *nested* within other decisions. Consider the following:

- Schedule:
- Holiday
- Weekend
- Weekday
- What time of day is it?
- Before office hours
- During office hours
- After office hours

- What time of day is it?

The above decision tree describes five final outcomes within two decisions. It doesn’t repeat the conditions to check if the current day is a weekday. The same approach can be used to create very complex decisions that are still easy to follow.