Computer science is the study of computers which includes both hardware and software design. It also studies the application of computer technology to science, business, and the arts. It is composed of several branches or sub-fields like computational complexity theory (involves properties of computational graphics), computer graphics (places emphasis on computation of specific results), artificial intelligence, software engineering, algorithms and data structures, programming methodology and languages, networking and communications, database systems, parallel computation, distributed computation, computer-human interaction etc.
A dissertation or thesis is a document submitted in support of candidature for an academic degree or professional qualification presenting the author's research and findings. In some countries/universities, the word "thesis" or a cognate is used as part of a bachelor's or master's course, while "dissertation" is normally applied to a doctorate, while in others, the reverse is true.