IGI is
International
Genealogical
Index part of LDS library at
www.familysearch.org (one of the first places you should check when researching a family although the Irish records there are not complete).
What is it you are hoping to find about Henry Meenagh and Elizabeth McAleer?
If they were born before 1864 there will be no birth certificate so you need to look for church baptismal records for names of parents, date of birth, address.
The actual civil marriage certificate will list their names, age (usually 'full age' put down unless under age in which case an age might be given), residence at time of marriage (not nec. where they were born or where their parents were living), occupations, fathers' names and occupations, names of two (usually) witnesses- also date and place of marriage and officiant. (Mothers' names, birthplace & date are not on marriage certificates).
