On August 22, 1661 Pepys refers to a Westphalia ham,
On June 8, 1667 and June 15, 1669 Sam refers to “a ham of French bacon” and “a ham of bacon”.
The definitions says that a ham can be cut from the hind leg of a pig or from other parts of the carcass, so it's a slightly less specific term.
On the other hand, bacon is pork meat cut from parts of the pig other than the legs, such as the back, loin, collar or the belly.
Other differences are that bacon is sold raw, and must be cooked before being eaten.
This information comes from https://wiltshirebacon.com/what-is-the-difference….
The traditional Westphalian Ham takes its name from the region of Germany where it was first developed. Pigs fattened on acorns produced the ham, then the meat was dry cured and smoked over the beechwood and juniper branches of the region.
This comes from https://schallerweber.com/product/westphalian-ham/
Well the confusion about what this means goes back to William the Conquer.
For many ideas, see https://behind-the-french-menu.blogspot.com/2016/….