What does 'bonded' means on an item?

Topic as per title. I see bows with bonded affixes, what does it mean?

“Bonded” on an item usually means that the item has a special interaction or connection with another item, skill, or mechanic. In Path of Exile, this typically indicates that the affix provides a bonus when certain conditions are met, like being linked to another item, gem, or status effect.

For bows, a “bonded” affix might give extra damage, attack speed, or another benefit when used in combination with a particular skill or support gem. Think of it as a synergy marker—it’s not just a passive stat, it triggers something specific.