The quick comparison
Stainless steel
The most versatile pan in the kitchen. Works at any heat level, goes from hob to oven, handles acidic ingredients without reacting, and can be scrubbed hard when dirty. The main drawback is that food sticks if the pan or technique is wrong. Pre-heat properly, add oil when the pan is hot, and let food release naturally. Fond — the browned bits that stick — is actually the basis of pan sauces: deglaze with wine or stock and scrape. See fond and deglaze in the glossary.
Cast iron
Excellent heat retention makes cast iron ideal for searing: it barely drops temperature when cold meat is added. Requires seasoning to maintain a non-stick surface, and should not be used with acidic foods (tomatoes, wine) for extended periods as acid strips the seasoning. Pre-heat slowly and evenly — 5–8 minutes over medium heat — then turn up for searing. According to Lodge Cast Iron, a well-seasoned skillet develops a progressively better non-stick surface over years of use.
Non-stick
The right tool for eggs, pancakes, delicate fish and anything that would destroy a pan's seasoning or create a cleanup nightmare. Never use non-stick at high heat — the coating degrades and can release harmful fumes. Never use metal utensils. Replace non-stick pans when the coating shows signs of peeling or flaking. BBC Good Food's guide to non-stick pans explains what to look for when buying.
Carbon steel
Used in professional kitchens for its combination of light weight (lighter than cast iron), high heat tolerance and good non-stick properties once seasoned. The classic wok is carbon steel. Treated identically to cast iron in terms of seasoning and acid avoidance. Takes more seasoning cycles to build up a good surface than cast iron. See the Serious Eats carbon steel pan guide for a detailed breakdown.
One pan to start with
If you own one pan, make it a 24–26 cm stainless steel frying pan or a 24 cm cast iron skillet. Either handles 90% of cooking tasks. Add non-stick only when you want to cook eggs without stress. See the knife care guide for the equivalent reasoning applied to knives.