Dictionary variables (Dictionary<TKey, TValue>) are collection type of variables of (key, value) pairs, in which the keys are unique. Think of the Address Book in your mobile phone, where each entry has corresponding data (name, phone number(s), email address, etc). The data types for both keys and values have to be chosen when the variable is declared. Data types within dictionaries can be any of the supported variables (String, Int32, etc) including Dictionary<TKey, TValue>. The operations that are most often associated with dictionaries are: Adding and deleting (key, value) pairs. Retrieving the value associated with a key. Re-assigning new values to existing keys. Methods for working with dictionary variables: Initialization As in the case of list variables, dictionary variables need to be initialized as well. For example, if we want to initialize a dictionary of String type of key and String type of value, we can add new Dictionary(Of String, String) inside the Default...