In Ireland and the UK, thesis usually means an unpublished work submitted for a doctoral degree (Ph.D) while a dissertation is a work produced at undergraduate or masters' level. Terminology is different in other countries.
Bambale, A. J. (2014) Facilitating the PhD research process: guides for identifying research problem and establishing research gap. International Journal of Business, Humanities and Technology. 4(1) pp.116-126
Faryadi, Q. (2012) How to write your PhD proposal: a step-by-step guide. American International Journal of Contemporary Research. 2(4) pp.111-115. Available at: http://www.aijcrnet.com/journals/Vol_2_No_4_April_2012/12.pdf [Accessed 21st December 2015]