CFD trades are standardised into lots, but each market has its own minimum number of contracts that aim to mimic how the asset is traded on the live underlying market.
For example, for share CFDs, the contract size is usually the equivalent of one share of the company you’re trading. For forex, there are standard lots which equal 100,000 units of the base currency, or mini lots that are equal to 10,000 units of the base currency.