Diablo 4 has several different currencies, upgrade materials, monster parts, plants, ore, & skins. This community-made infographic shows the use of each of these currencies and materials, as well as how each of them can be found!
Crafting Materials and Currency Source Guide Where to Find ‘Crushed Beast Bones’
Infographic created by ThatJumpyJumpS on Reddit
Since materials and currencies in Diablo 4 are account-wide, there’s no reason to worry about farming them on different characters.