What is CRISPR technology and how could it change the way we treat and cure diseases?

I keep hearing about CRISPR as a revolutionary technology in medicine but I do not fully understand what it is or how it works. Can you explain what CRISPR is in plain language without technical jargon? How does it work as a gene editing tool and what makes it different from previous approaches to treating genetic diseases? What diseases is CRISPR currently being used to treat or cure, including sickle cell disease, cancer, and inherited conditions? Are there any CRISPR-based treatments that have already been approved for use in patients? What are the risks and limitations of CRISPR as a medical treatment and what are the ethical concerns around editing human genes? How accessible are CRISPR therapies likely to be for people in developing countries and low-income settings where diseases like sickle cell anaemia are most common? And what does the future of CRISPR medicine look like over the next ten to twenty years?