A neutral material has the same number of protons and electrons. If a material gains electrons it has more electrons than protons, so it has an overall negative charge. We say it becomes negatively charged.
The material that loses those electrons is left with more protons than electrons. Its overall charge is positive, so it becomes positively charged. No protons have moved. The material is positive only because some of the negative electrons have gone.
Every electron that leaves one material arrives on the other. The number gained equals the number lost, so the two charges are equal in size but opposite in sign. For example, if 200 electrons move from a cloth to a rod, the rod has 200 more electrons than protons and the cloth has 200 more protons than electrons. The total charge of the two together is still zero, because charge is never created or destroyed.