Though the word 'Vachana' literally means 'whatever spoken', it has been used in the Vachana-literature in several senses. For example, it may refer to the words of Agamas; or to those of the Vedas and other ancient literature; or to any true statement; to a promise; or to any word [1:100]. However, Vachana as a form of literature means prose, which has the flow and spirit of poetry. While poetic forms (for example, sonnet) have their own rules, Vachana is free from rules. In fact, originally the Vachanas were written as poems. Perhaps they were actually sung like songs, as is done occasionally at present.
In any case there is a fundamental difference between Vachana and poems. Those who write poems (like sonnet, or of others forms) have to observe the rules of prosody and the like, and may be written by anybody under the sun. However, Vachanas are believed to the utterances of mostly mystics or, at least, saints. The usual themes of the Vachanas, namely, the highest reality, liberation (Lingānga-sāmarasya, [ಲಿಂಗಾಂಗ ಸಾಮರಸ್ಯ]), the real nature of the self, etc. have authenticity only if they are statements of mystics. In this sense, we do not ask whether the words of a poet are authentic. Secondly, the Vachanas have for their subject matter God, soul, liberation, necessity of moral life, merit of spiritual life, etc; and poems may deal with human relations, erotic love, etc. which are far more removed from spiritual life.
[1:100] : 100th Vachana in the 1st Volume, (Samagra Vachana-Samputa in 15 volumes)
Publisher: Kannada Pustaka Pradikhara Govt of Karnataka, Bangalore, 2001.
|Sadhakya [ಸಾಧಕ್ಯ]||Vibhoti or Bhasma [ವಿಭೂತಿ or ಭಸ್ಮ, ಭಸಿತ]|
 From the book "Vachana", pub: Basava Samiti Bangalore 2012.