Hugs and kisses or xoxo is a term used for expressing love, affection or good friendship at the end of a written letter, email or SMS text message.
The common custom of placing X's on envelopes, notes and at the bottom of letters to mean kisses dates back to the Middle Ages, when a Christian cross was drawn on documents or letters to mean sincerity, faith, and honesty. A kiss was then placed upon the cross, by the signer as a display of their sworn oath. It was also used in early Christian history as much of a display of the same. Since most of the common people could not read or write, the 'X' was placed on documents, and a kiss placed upon it as a show of their sincerity. The Chi Rho, often represented with the letter 'X', was also used as a holy symbol throughout Christian history as it represented the Greek word for Christ ΧΡΙΣΤΟΣ; this gave rise to the practice of using the letter 'X', which was then kissed in this tradition of displaying a sacred oath.
The 'O' is of North American descent; how it was started is unclear. Perhaps the 'O' being rounded represents arms encircling another, as in an embrace. Another possibility is that it is the other character used in Tic-tac-toe, and signifies 'hugs' as in the common phrase "hugs and kisses".
See also