Writing systems galore

Please check out www.omniglot.com! It's an excellent site on various writing systems for various languages. It breaks them down into Alphabetic, Syllabic, Logographic, Undeciphered, and Alternative Writing Systems.

Alphabetic systems refer to writing systems that represent individual consonants or vowels. There are apparently some that only have symbols for consonants.
Syllabic systems refer to symbols that represent consonants and vowels.

What the heck are Logographic writing systems? Hm....