Sometimes, instead of holding a note for its full value, you can start on a note (e.g., a bent note) and immediately move to another note. These very quick notes are called grace notes. Bent grace notes can be thought of as a wah sound produced by the mouth. The "w" is the grace note and the "ah" is the following note held for its usual length of time.
Bent grace notes are indicated in the notation by the letter w above the note to which it applies.
Here is a lick making use of grace notes. This one also contains a slide, which is actually another method of producing grace notes.
Here is another lick containing both slide and bending grace notes.
This 12 Bar Blues in the key of G sums up all of the techniques presented in the lesson. It also contains double stops (2 notes played together). Then try to memorize the solo one lick at a time.