When Magic Booster is used in the 2013 PC re-release, the player's inventory gains 100 Silence spells, among other basic spells.
Silence can be drawn from many enemies at all levels, and can be refined from Silence Powders using the Guardian Force Diablos' ability ST Mag-RF. This makes Grats a good source of Silence, for both the Silence Powders and to draw the spell, and Grats are available to fight since the beginning of the game in the Balamb Garden training center.
Silence will inflict the Silence status effect on a target that is not immune to it. This renders the target unable to use spells (and renders party members unable to summon).
Silence can be cast using the Magic command, Selphie's Slot Limit Break, or Rinoa's Angel Wing if she has it in her inventory. Casting Silence in battle increases compatibility with Siren by 1.6, and with Doomtrain by 1, but lowers compatibility with Cerberus by 0.4 and with Carbuncle by 0.2.
Silence can be junctioned to ST-Atk-J to inflict Silence on enemies with a physical attack, allowing a character to permanently inflict Silence against enemies that are vulnerable to it. This can be useful against enemies and bosses that primarily cast spells, such as Propagators. However, junctioning Sleep to ST-Atk-J can in a lot of cases have a similar desired effect, meaning it is best to do this only in instances where an enemy is immune to Sleep but not to Silence. The Guardian Force Siren inflicts all enemies with Silence in conjunction to dealing damage, possibly making it the superior attack to the Silence spell.
Silence can also be junctioned to ST-Def-J to resist against Darkness, and 100 Silences can lead to immunity to it. While this is useful if the player is using a party member as a mage to cast spells, casting spells is less common in Final Fantasy VIII.
In both cases, Silence is outclassed by Pain. This is because Pain can not only inflict or provide full resistance to Silence, but also has the same effect for Darkness and Poison. As a result, Pain can provide full immunity to three statuses with on ST-Def-J slot, or inflict three statuses with the ST-Atk-J slot, making Silence redundant. In this case, Silence is only useful in the event where the player wants to inflict or resist against Silence but is using Pain to junction to stat boosts (as Pain is useful in this regard).
The following enemies use Silence against the player party: Abadon, Blobra, Blood Soul, Cerberus, Edea (2nd), Forbidden, Gargantua, Gerogero, Gesper, Glacial Eye, Imp, NORG, Paratrooper, and Propagator. It can be reflected.