Capital gain on property
A capital gain on property is the profit made by selling a property for more than it cost, purchase costs and works included.
The sale of your main residence is exempt. For other properties, the tax treatment depends on how long you have owned them: a quick resale is taxed as a speculative gain, a later resale benefits from a more favourable regime.
Rules and allowances change: for a buy-to-let or second home, it is wise to have the tax calculated before setting the price.