On the other extreme, simple problems can be constructed that are very instructional and illustrate ideas in chess strategy and tactics. Often these can be solved in less than a minute by people who understand the principle involve. These are frequently used in chess instruction. Chess problems range from being easy for a beginner to solve to being difficult for a master to solve. Most newspapers that have chess columns will also have chess problems.
Chess problems are also very useful in helping develop thinking skills.
A special type of chess problem, popularized by Raymond Smullyan, utilizes retrograde analysis, in which the solver must determine how key pieces in a problem got to the squares on which they are shown. This enables the solver to gain experience working backward from a known situation to infer what happened in the past. Most online sites and chess servers allow chatting and observing as well as playing. Whether you want to play, observe games played by top level players, take chess lessons, or simply discuss chess ideas with others, you should consider going to an online chess site. There are several common types of online chess sites.