Frequency counters are a type of algorithm used to count the frequency of elements in a collection. They are commonly used in computer science and data analysis to analyze large datasets and identify patterns. The basic idea behind a frequency counter is to iterate through the collection and keep track of the count of each element encountered. This can be done using a data structure such as an array or a hash table. By counting the frequency of elements, frequency counters can provide valuable insights into the distribution of data and help in making informed decisions.