sashikomi

Sashikomi  

is a sashikomi that threatens to cut at a or b.

Approach  

Black just approached (tsume), threatening an invasion at a. White could defend at b, but has a better option: probe at c.

Inside connection  

If Black connects inside, White defends and can later exploit the weakness (aji) at a.

Outside connection  

If Black connects outside, White plays forcing moves (kikashi) until the weakness at a is gone, allowing White to grab the initiative (sente) and play 11 elsewhere.