You rent computing power. To mine 1 BTC, you need the miner to be configured and working. Electricity, the work of engineers, supplies: all included in the service charge. The contract works only with paid service. You can do this when purchasing and in your personal account. You just have to not worry and get your daily income in BTC.
From you: from the hashrate (TH / s) of your contract/miner and their duration.
From us: how cheap we get electricity and how well the equipment is set up.
From higher powers: how difficult is it to get 1 coin and from its course right now.
A cloud mining contract requires less investment than a miner, but also brings less profit. The miner is more expensive, but more profitable in the long run. To get acquainted with the world of mining and bitcoins, a cloud mining contract is better suited, for maximum profit, it is better to buy a miner.