Atoms can gain or lose an electron, losing their electric neutrality and turning into ions.

If an atom picks up the electrons that another loses it becomes a negative ion or anion.
The atom which loses electrons turns into a positive ion or cation.

The particles which are transferred from one atom to another are always electrons, never protons.

Macroscopic bodies can also be electrified. How?

The most simple method is to rub one against the other.

Try the following experiment yourself: take two sheets of plastic of the type you use to separate the pages in a folder, and keeping them separate, rub them with a cloth for a few seconds. Then move them nearer to each other and observe how they repulse each other.

Lastly, move one of them near to the cloth and see how it is attracted to it.
The explanation is that when you rubbed the plastic sheets with the cloth there was a transfer of electrons between the sheets and the cloth, so that the sheets were charged with the same sign and the cloth with the opposite sign.