A computer technician always touches the metal body of a computer before touching any of its electrical parts. why?

Computer technician always touch the metal body parts of the computer before touch any electrical part of the computer because it will neutralized the body static charge.

The components of the computer are made up of the materials with the positive and negative charge electron and their electric effect basically neutralized the one another.

while touching any electrical hardware make sure that the electricity is off and discharge our body from any static charge. Also avoid wearing wool clothes when touching any electrical hardware parts as they also build static charge.