A Verbal that helps to restore lost Vitality. Typically a character will state how much healing they are providing, otherwise the default amount is 1 if they only say "Heal" without any numbers or modifiers. From the Accelerant core rules:
"This effect restores one point of Vitality. If the effect is followed by a number, then it restores Vitality equal to the indicated number. Otherwise it restores one point. If you are unconscious with no Vitality then healing will restore one or more Vitality points and you will wake immediately unless some other effect is preventing you from doing so. Heal is a beneficial effect."
Other characters may attempt to touch you with a Packet to try and heal you, or in some cases they might throw the packet at you so that you get the healing even if they're not able to walk up to you. You may also hear it delivered via By My Voice calls.
There are a variety of game abilities that will allow a character to heal, and they will typically state what is allowing them to give you the healing, such as "Heal by Magic" or "Heal by Inspiration".