What is the difference between texto and teksto?

First you must consider the origin of those words. for example, old filipino people use teksto with a K on it before a more modern people came.  Then after some time, especially upon the Spanish colonization, many people use texto with X.

A text is primarily a collection of symbols or signs with their own meaning.

TeXto – considered to be the nontraditional readings, such as: T.V. Internet, T-shirt, I.D.

TeKsto – the traditional readings. example: Bible, Pocketbook, Magazine, Newspaper.