classical economics is an economy that runs best when left alone
The core idea behind the classical economics born in the 18th century by Adam Smith when he published his book titled "The Wealth of Nations" is a Free Market System.
Smith introduced many things like the Invisible Hand (demand and supply as the prevailing market guide) and also the idea that with millions of people each pursuing their own self-interest (selfish interest) unknowingly creates balance in the economy for example when a baker bake's bread they're not thinking about feeding the Society with breads but they're trying to make money and profit and because of this selfish pursuit of money and profit it ensures people get their daily bread and the economy is productive
classical school also believes that prices, wages and markets naturally adjust themselves
For example if bread becomes too expensive bakers will see an opportunity to make money and more Bakers enter the market increasing Supply and bringing down prices
According to the above curve at equilibrium quantity demanded is equal to quantity supplied and price is P but if price is increased to P1 quantity demanded reduce because people buy less when price is up and this action will increase the quantity supplied which will create excess supply and lead to price going back to P which means the market readjusted itself.
But we've seen instances where increase in prices didn't lead to reduce demand and didn't eventually lead to excess supply so which makes this particular theory problematic.
The classical school also believes that if wages in one industry are high workers move there until wages balance out but it doesn't always work that way there are many things that decides wages not just movement of workers from one company to another
