Only the words that are made up of them do. The individual letters in a word don't mean anything. By themselves, they simply indicate what sound you're supposed to make. For example, the letter s indicates the s sound (which sounds like ssssss).
About Rupert Boneham. Rupert Boneham (born January 27, 1964) is an American mentor for troubled teens, who became known to reality television audiences in 2003 as a contestant on Survivor: Pearl Islands where he placed 8th. He later appeared on the All Stars, Heroes vs. Villains, and Blood vs. Water seasons of Survivor, placing 4th, 6th, and 20th respectively.
Hewlett first gained fame for his role as Grant Jansky in the 1996 Canadian TV series, Traders and a year later, appeared as David Worth in the 1997 Canadian psychological horror film Cube. He later played bad-tempered airplane pilot, Douglas Hunsiker in the 2011 movie, Rise of the Planet of the Apes.