How do shakespearean sonnet different from a petrarchan sonnet?

Shakespearean Sonnet

* 14 lines

* Iambic pentameter

* 3 quatrains and a couplet

* Rhyme scheme: ABAB CDCD EFEF GG

Petrarchan Sonnet

* 14 lines

* Iambic pentameter

* 2 quatrains and 2 tercets

* Rhyme scheme: ABBA ABBA CDCDCD or CDECDE