Yes, “weapons grade” has a higher purity being almost entirely made of fissile isotope Pu-239
“Reactor grade” has a greater variety of isotopes.
The functional difference is that the higher purity is required to make nuclear bombs, hence “weapons grade.” Purity was a significant hurdle in nuclear arms development and one if the reasons the US got the bomb before Germany or the USSR which both struggled to get sufficient purity.
Yes, “weapons grade” has a higher purity being almost entirely made of fissile isotope Pu-239
“Reactor grade” has a greater variety of isotopes.
The functional difference is that the higher purity is required to make nuclear bombs, hence “weapons grade.” Purity was a significant hurdle in nuclear arms development and one if the reasons the US got the bomb before Germany or the USSR which both struggled to get sufficient purity.