A or c because I have a feeling that it might be
The term that would best be applicable to the character that divides entries from one another for convenience would be a delimiter. In addition, these delimiters comprise sequences in which they are intended to indicate a boundary between regions of independent data streams and other texts.
HashSet changes the array to be in alphabetical order. It also removes any items that are in the array twice.
A search engine only searches specific things, while a web browser you can search whatever you want