What are the main differences between a SEO and a SEM?

SEO (Search Engine Optimization)  - It is the process of improving a website's or web page's visibility in search engine result pages (SERPs). SEO entails a variety of techniques such as keyword research and analysis, content optimization, link building, and website structure optimization. The goal of SEO is to increase organic traffic to a website by improving its ranking in search engine results pages (SERPs). To accomplish this, SEO strategies must be tailored to the specific target audience and must emphasize the creation of quality content that is relevant to the target audience. SEM (Search Engine Marketing)  - It is the practice of marketing a company through paid advertisements that appear on search engine results pages (SERPs). SEM is an efficient way to increase website traffic, raise brand awareness, and potentially increase sales.