* Closed Syllable: A closed syllable ends in a consonant sound. The vowel sound is typically short. Examples: *cat*, *dog*, *pin*, *cup*.
* Open Syllable: An open syllable ends in a vowel sound. The vowel sound is typically long. Examples: *go*, *me*, *he*, *sky*. Note that the "y" in "sky" acts as a vowel in this context.
Essentially, the presence or absence of a final consonant sound determines whether a syllable is open or closed.