The precise definition of these two types of footwear is not clear for one mixes gradually into the other. Sabots are traditionally made entirely of wood, while galoshes are made with wooden soles and leather uppers.

Grandrif had six makers of sabots and galoshes. One of them was our neighbour's father
In this detail of a 1924 photo of the children at Grandrif Public School, there are two boys wearing sabots, while two others wear a form of galoche that look like boots.
There was a leather band over the upper to make them more comfortable. On the small sabots of the children, this band could be unbuttoned.
Nowadays clogs and galoshes may seem old-fashioned, but it is still possible to buy them. The difference is, in the past, they were cheap, today they are fashionable and, as a result, very expensive.
LES SABOTS
Les sabots par Van Gogh