Both algorithm learn one-variable patterns. A one-variable pattern is a word that can also contain the variable symbol x. E.g., bxabxaa is a one-variable pattern. The language generated by a one-variable pattern consists of all words you get when you substitute a non-empty word for the variable symbol in the pattern. The language of bxabxaa contains, e.g., the word bbababbabaa, which you get by substituting bab for x.
One-variable pattern languages are a very simple class and are well suited to serve as an example of a learnable concept.
If you provide enough examples, you will get the correct answer eventually.
If you press the button labeled ``Learn'' the algorithm answers with a descriptive one-variable pattern.
The algorithm presents a pattern p and you have to answer yes if the language generated by your pattern is contained in the language generated by p. Otherwise you have to answer no.
If you answer no the algorithm may ask you for a counterexample. In that case you are asked to enter a string that is contained in the language of your pattern, but not in the language of p.