Scenario vs. Scenario Outline

From the official guide:

Copying and pasting scenarios to use different values can quickly become tedious and repetitive:

Scenario: Eat 5 out of 12
  Given there are 12 cucumbers
  When I eat 5 cucumbers
  Then I should have 7 cucumbers

Scenario: Eat 5 out of 20
  Given there are 20 cucumbers
  When I eat 5 cucumbers
  Then I should have 15 cucumbers

Scenario Outlines allow us to more concisely express these examples through the use of a template with placeholders

Scenario Outline: Eating
  Given there are <start> cucumbers
  When I eat <eat> cucumbers
  Then I should have <left> cucumbers

  Examples:
    | start | eat | left |
    |  12   |  5  |  7   |
    |  20   |  5  |  15  |

The Scenario Outline steps provide a template which is never directly run. A Scenario Outline is run once for each row in the Examples section beneath it (except for the first header row).

More in the Writing Features guide.