Power tells you what can start
Watts describe the rate at which power is delivered or consumed. A station's continuous output rating tells you roughly how much load its AC outlets are designed to support. A separate surge or peak rating may describe a short startup allowance for motors and compressors.
A device with high startup demand can trip or overwhelm a station even when its day-to-day running watts are modest. This is why an appliance's label and manual are more useful than a rough category label such as kettle or refrigerator.
Watt-hours tell you how much energy is stored
Watt-hours describe energy over time. One hundred watts used for two hours is 200 watt-hours, subject to conversion losses and the system's usable limits. A battery with a high watt-hour rating can run a low-power device for a long time while still failing to power a high-wattage appliance.
When estimating runtime, use the actual load profile rather than a simple continuous average. Cycling motors, heating elements and standby consumption behave differently.
Use a two-column comparison
Create one column for output watts and surge, and another for stored watt-hours. Add recharge watts, outlet types and weight underneath. This prevents a large-capacity unit from being compared with a smaller but more powerful inverter as though capacity were the only difference.
Then test the candidate against your own load list. The best-labeled product is not necessarily the best fit if it cannot start the appliance you need or cannot be recharged within the outage scenario.
Evidence note
This article explains general electrical terms and does not certify a specific product configuration.
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