how to imply and define casual interference and separate it from bias

Review “Why Causal Inference Matters to Nurses: The Case of Nurse Staffing and Patient Outcomes,” located in https://ojin.nursingworld.org/MainMenuCategories/ANAMarketplace/ANAPeriodicals/OJIN/TableofContents/Vol-21-2016/No2-May-2016/Why-Causal-Inference-Matters-to-Nurses.html
How would you define and imply causal inference relative to your quasi-experimental designed project and separate it from bias and other factors that may influence it?