This value is 0,2 g hydrogen.
The reaction you've provided is the decomposition of hydrogen peroxide (H2O2) into water (H2O) and oxygen (O2). This is a decomposition reaction where hydrogen peroxide breaks down into its constituent elements.
I think of decomposition as organic processes. For example wood rotting (or anything else rotting). However, decomposition can also be a chemical process. For example, if you heat wood chips sufficiently without fire, or without inadequate oxygen, they will decompose into a mixture of light gasses often termed as wood gas.