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.
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. Indicates any single alphanumeric character. Specifies zero or more alphanumeric characters. Specifies a range of characters in a set.