The Comedy of Errors is light, frothy entertainment, driven by coincidence and slapstick humor, its events confined within a single day. There are hints of Shakespeare's later forays into deeper character development, especially in the early laments of Antipholus of Syracuse for his missing twin, but the story remains largely on the surface. Characters are mistaken for one another, but they do not pretend to be other than what they are--there are no disguises here, only resemblances. The plot, so concerned with outward appearances, appropriately turns on the exchange of material objects--a Courtesan's ring, a gold chain, and the thousand marks that Egeon needs to save his life. Virtually all interior life is absent, and the action is entirely physical.
There are intimations of disturbing, even tragic issues in the story, of course--the plot depends on an initial threat of execution, and the play is filled with unsettling subjects. There are broken families, a troubled marriage, slavery, grief and anger, frequent violence, and a beheading lying in wait at the end of the day. But the play is not about these issues--it touches them briefly before skating on to happier, funnier subjects. The audience's moments of unease are brief and quickly give way to laughter.
And indeed, because this play is a comedy, everything that threatens the laughter is eliminated at the end. It is not only the characters' confusion that is relieved by the final scene, in which the "errors" are explained and resolved; all the darker, unpleasant issues are resolved, as well. Duke Solinus begins the play as a figure of unbending, almost tyrannical legalism; he ends it as a forgiving father figure. The broken halves of Egeon's family have been separated for more than 20 years; now they are put back together, and wife and husband fall into one another's arms as if time and distance had not intervened between them. The marriage of Antipholus of Ephesus and Adriana is threatened by mutual jealousy; their reconciliation, once their misapprehensions have been cleared away, is the work of a few moments. And even the poor, abused slaves, the Dromios, quickly forget their beatings and bruises and embrace. The ease with which these problems are overcome points to the central theme of the play: Love and felicity will triumph over all.
I have written my own act wise summary of comedy of errors. Hope it will help students like me.