For example vertice A connected to vertice B and vertice C connected to vertice D? Would this be considered two different graphs? Here is a graph, would it be bipartite?
Re: can a bipartite graph have two not connected parts?
A bipartite graph can be disconnected. Wikipedia says: "One often writes $G=(U,V,E)$ to denote a bipartite graph whose partition has the parts $U$ and $V$, with $E$ denoting the edges of the graph. If a bipartite graph is not connected, it may have more than one bipartition; in this case, the $(U,V,E)$ notation is helpful in specifying one particular bipartition that may be of importance in an application".