7 x 9 in/17.8 x 22.9 cm
First. Let's get the pronunciation right. It's poh-SHOD with the accent on SHOD. It's French.
Actually it's French for the word poche or pocket, according to Wikipedia. I suppose that's pocket, as in a painting small enough to fit in your pocket or almost anyway. It is a small sketch-like painting that "captures the color and atmosphere of a scene."
You may also be familiar with the term pochade box, which is a type of portable easel popular for en plein air painting. It's like a Swiss-army-knife for painters, in that in addition to being an adjustable easel, it's also a stand and a paintbox with partitions that folds up and can be carried under one arm. But I'm not talking about that pochade box.
I'm talking a pochade as in a small painting.Why paint a pochade?
A pochade makes a great study for a bigger painting either en plein air or in the studio.
A pochade allows you to paint only the main elements, due to its small size.
A pochade or more accurately the support on which you paint a pochade can be paper, wood, canvas (or other) and is relatively inexpensive, again due to its small size.
A pochade can be and maybe should be painted rather quickly.
A pochade makes a great small painting and a statement all by itself, especially framed.
Painting a pochade is fun.