In residential settings, the most common circuit breakers are single-pole, double-pole, GFCI, and AFCI. Single-pole breakers protect a single wire, provide 120 volts, and are typically used for lighting and outlets. Double-pole breakers protect two wires, provide 240 volts, and are used for large appliances like water heaters and HVAC systems. GFCI breakers prevent electric shock in wet areas like kitchens and bathrooms. AFCI breakers detect arc faults, reducing the risk of electrical fires, and are commonly used in bedrooms and living spaces. Each type has pros and cons. Single-pole breakers are affordable but not suitable for high-capacity appliances. Double-pole breakers handle large loads but cost more and take up extra space. GFCI breakers enhance safety but can experience nuisance tripping. AFCI breakers prevent electrical fires but may be overly sensitive to some devices. To replace a circuit breaker safely, turn off the main power, remove the panel cover, and test for voltage. Disconnect and remove the faulty breaker, install the new one, and secure the wiring. Replace the panel cover, restore power, and test the breaker. This process takes one to two hours. Essential tools include a screwdriver, voltage tester, and a matching replacement breaker. To add a breaker to an electrical panel, ensure there is available space, turn off the main power, and test for voltage. Prepare the slot, route the appropriate gauge wire, connect it to the breaker, and secure the breaker in place. Organize the wiring, replace the panel cover, restore power, and test the circuit. This process takes two to four hours. Required tools include a screwdriver, voltage tester, wire stripper, appropriate electrical wire, and a circuit breaker matching panel specifications. Electrical work can be dangerous. If unsure about any step, consult a licensed electrician to ensure a safe and compliant installation.