They are concepts used by Marx to explain the progression of human society through distinct phases. In general terms a thesis is a starting point, an antithesis is a reaction to it and a synthesis is the outcome. Marx developed the concept of historical materialism whereby the history of man developed through several distinct stages, slavery, feudalism, capitalism and in the future communism. The movement from one stage to another could be explained by using thesis, antithesis and synthesis.
Sardonic: Definition and Examples | martinealaplage.info
This is based on the logical phrase or term. Antithesis can be defined as "a figure of speech involving a seeming contradiction of ideas, words, clauses, or sentences within a balanced grammatical structure. Parallelism of expression serves to emphasize opposition of ideas". An antithesis must always contain two ideas within one statement.
The triad thesis, antithesis, synthesis is often used to describe the thought of German philosopher Georg Wilhelm Friedrich Hegel. Hegel never used the term himself, and almost all of his biographers have been eager to discredit it. According to Walter Kaufmann, although the triad is often  thought to form part of an analysis of historical and philosophical progress called the Hegelian dialectic , the assumption is erroneous. Hegel used this classification only once, and he attributed the terminology to Immanuel Kant. The terminology was largely developed earlier by the neo-Kantian Johann Gottlieb Fichte , also an advocate of the philosophy identified as German idealism.
Thesis and antithesis are literary techniques used to make a point during a debate or a lecture or discourse about a topic. The thesis is the theory or the definition of the point under discussion. Antithesis is the exact opposite of the point made in the thesis. Anti is a prefix meaning against. The antithesis therefore goes against the thesis to create an opposition effect.