The searching flexibility is an important characteristic of fulltext retrieval systems. Textual searching can take many forms. The complexity of searching can range from a simple word search to boolean queries with proximity distance and regular expressions. OK, I'll explain that obnoxious jargon. They would have to be within some specified distance of each other.
Distance is described as a stated number of words.
Regular expressions are a formal way of using a pattern to represent many letters. You are probably already familiar with the concept of wild carding for file names. More complex regular expressions are commonly used in the UNIX operating system and as a way to specify text for retrieval and editing. These types of searches were previously used only by techno-geeks. Now however with the advent of the Web doing them is becoming a more important skill.