Strong, artificial, forcing 1-round, with 20+ HCP , or a 9+ tricks hand .
Normally responses are like this:
2D = 0-5 HCP
2H/2S/3C/3D = 6 HCP + and at least 5 card
2NT = 6 HCP + and a hand withot 5 card
There are several other ways to respond. Some use 2D as a
waiting bid were opener must describe hand. Other use control responses. Those
who play woodgroves multi should look at woodgroves 2C