If you omit the commas, the query is then treated as a phrase. By default, a simple query searches for words, not literal strings.
Case is ignored in searches.
A simple query expression is somewhat more powerful than an explicit expression since it employs operators by default. A simple query employs the STEM operator and the MANY modifier. The MANY modifier forces the documents returned in the search to be presented in a list based on a relevancy score. The more frequent the occurrence of a word in a document, the higher its score. The following chart illustrates wildcard characters which may be used in both Simple and Explicit queries.