The body of the patent, or specification, often describes many features, but the things described there are not necessarily protected. In general, to analyze patent coverage, look at a competing product or service and read your patent claim line by line. If the competitor meets every requirement in the claim, there is infringement. If the competitor leaves out just one feature included in the claim, there is generally no infringement. The coverage is broad if competitors have difficulty avoiding the patent claims.
Prior art includes prior patents, other products, and publications that pre-date the invention.
A pending patent provides no protection. Patents are also not self-enforcing. However, if a competitor proceeds anyway, and does not respond to threatening letters, the patent rights must be enforced in a lawsuit. Patent lawsuits may cost hundreds of thousands of dollars, putting them beyond the reach of most early-stage entrepreneurial companies. Most of the work occurs during initial preparation of the application, so these costs are front-end loaded.