18. The context based conversation system as claimed in claim 13 further comprises a maintenance module, executable by the processor, to, move the facts from a user graph or the context graph to a factstore over a period of time; and cleanse the context graph to remove irrelevant data from the context graph.
13. A context based conversation system comprising: a processor; an authorization module, executable by the processor, to, receive user data from a user, wherein the user data comprises login credentials of the user and metadata associated with the user; based on the user data, determine a role of the user, wherein the role of the user is pre-defined, and corresponds to one of a registered user, a guest user, and an administrator; and provide restricted access to the user, based on the role pre-defined for the user upon ascertaining access privilege of the user; a parsing module, executable by the processor, to, receive text input from the user, wherein the text input is in natural language; parse the text input to convert the text input from natural language to functional language; based on the parsing, generate an expression from the text input; and a classification module, executable by the processor, to determine the type of expression from one of a discussion, learning, unlearning, wherein the expression is processed semantically and contextually upon determining the type of expression, wherein the expression is generated using a position of a particular word in the text input and the generated expression provides flexibility to use the same expression for text inputs with different semantic meaning but same syntactic form; invoke, based on the determination, one of a discussion service, a learning service, and an unlearning service; and retrieve a response based on the expression and the provide the response to the user, obtain conversation data from the discussion service, the learning service, the unlearning service, the metadata associated with the user, user persona data for registered users to include in a context graph, wherein the context graph enables the context based conversation system to retain a conversation history that aids in identifying a domain of the conversation with a timestamp.