Protectors are parts (aspects) of your internal system who want to help you live a safe and flourishing human life. In their healthy and natural states, they are nothing short of what makes you human. Protectors allow you to do the things you do. The Self (the intrinsic leader of your system, and the one who carefully guides all the other parts) is simply being: offering clarity, compassion, courage, confidence.
Self is the human be-er. Protectors are the human-doers.
Managerial Protectors (Managers) are proactive: they attend to our appearance, our behaviors, our money, our children. They help manage our relationships and even our bodies. Examples of common Manager Parts include organizers, time-keepers, fashion-advisors, shoppers, planners or social justice activists. At their best, they support us well. In their right roles, they are our Self’s support staff.
…However, each of us has experienced setbacks, harms, and wounds in life. Therefore, our Protectors are often over-vigilant and out-sized. They come out of their naturally healthy states and perform in heightened ways. When this happens, they often do more harm than good even thought their intentions are always good. Examples include parts that worry or catastrophize. Parts that criticize, self-berate, over-analyze, procrastinate, intellectualize, act blank, or complain. They take responsibility for everything because they are not connected in a healthy way with your Core Self. In fact, these extreme managers often don't even know You (your Self) exists.
Firefighting Protectors (Fire Fighters/Distractors/Soothers) are reactive: they show up after a younger or more vulnerable part in you has been triggered. They rush in to save the day by distracting, numbing, and soothing the hurt part. They want to hide it away so it’s safe and so it doesn't get hurt again. Examples include: rage, aggression, over-eating, binging on alcohol, drugs, sex, Amazon purchases, or Netflix, numbing out, freaking out. They don't know about the Self. They don't care about the Self. They have one job: put out the internal fire and calm things down.
Rennie’s addition: when protector parts have been completely unburdened (happening only after Exiles are unburdened and healed) these parts can shift into completely healthy roles - their natural states - where each one expresses Self-energy in a particular way (like Wynton Marsalis’s jazz playing part in flow or an experienced CPA invoking their master accountant part working on your tax returns). Some of these parts choose to maintain a healthy protector-relationship with the system. Others choose to shift entirely, no longer protecting at all. Instead they become healthy Actualizers working in alignment with the Self, bringing into being the true nature of an individual human being in that person’s particularity. (Although this term isn’t part of the standard IFS lexicon, I suggest that it could be.)