What poker ranks next above a straight?

A flush

A flush is 5 cards of the same suit that are not sequential.

Example of a Flush:

2 of hearts (♥)

5 of hearts (♥)

7 of hearts (♥)

8 of hearts (♥)

King of hearts (♥)

Not a Flush:

4 of clubs (♣)

5 of clubs (♣)

6 of clubs (♣)

7 of clubs (♣)

8 of clubs (♣)

(The above would be a "straight flush")