Suppose if we have 100 records in the database.In that 100 
records we have 3 records with name Johnsmith, John and 
John smith.If we use exact match for Johnsmith only record 
will come with name Johnsmith.if we use match 3 records 
will come with name Johnsmith,John and John smith.If we use 
ignore space 2 records will come with name Johnsmith and 
John smith.Ignore space will ignore spaces when spaces are 
present inbetween,exact match will check for the exact name 
even it checks for the spaces too,match it checks only for 
the keyword.suppose u use match for the word john it will 
give 3 records with the above names.