Grounding
Grounding means making objects neutral or uncharged. If it is negatively charged than taking its electrons or if it is positively charged than make it gain electrons. Universe has excess amount of electrical charges, electrons and protons. This huge resource makes all charged particles neutral we call this process as grounding. Look at the given example that shows grounding process of positively charged matters and negatively charged matters.
First sphere is negatively charged. When we connect it to ground excess amount of electrons flow to the ground and sphere becomes neutral. In the second sphere, it is positively charged. As you learned before, protons cannot move, thus electrons with the same amount of protons must come to the sphere to make it neutral. Sphere attracts the electrons from the ground and becomes neutral.
In the first picture, there is a neutral sphere. We want to charge it positively. First, we put a negatively charged rod near the sphere that repels the electrons right side of the sphere and protons stay at left side of the sphere. After separation of the electrons and protons we apply grounding to the sphere and make electrons flow through the earth. Finally, after the completion of electron flows we break the grounding and take the negatively rod away. We negatively charge the sphere with the help of grounding and induction.