As its name depicts the book was all about the political ideology of overthrowing the" bourgeois" and bringing the working classes ("the proletariat) to power. This philosophy later came to be viewed as Communism or Marxism. The book was revolutionary where the "proletariat" that is the working classes were asked to Unite based on the ideology of achieving a classless society. This book has been held to be the basis of many political ideologies which later came to form the crux of the socialist/communist revolutions perpetrated by revolutionists like Vladimir Lenin, Joseph Stalin and other political leaders. The Book is not just a political agenda but a basis for a certain economic condition based on the "benefit of the Community" (hence the term Communism).
In this way The Communist Manifesto not only discusses the relationship between the Communists' theory of history and the relationship between proletarians and bourgeoisie,(part 1),but goes on to discuss how the communists can help the working classes(proletarians) in part two.However the book has addressed what it calls the shortcomings of previous similar revolutions and why they failed to achieve what they had set out for (Part 3) and last but not the least the book gives guidance on how the Communists should interact with the other political ideologies or parties to promote their own benefit.
Marx and Engel have pointed out how the Class Struggles and suppression of the Proletariat or the working class has to stop because it has crossed all boundaries. They have spoken of the "March in History" triggered by the breaking down of Class relationships due to this increased suppression and the new age of technology particularly the breakdown of feudalism. The conflict of the classes society is thus the Bulwark of the modern Industrial times which are pregnant with change due to the increased damage done by the selfish philosophy of the exploitative concept of Capitalism which denies these suppressed minorities of their rights and offers them little in terms of fair compensation. For Marx and Engel this manifest unfairness will lead to a unique revolution where the tables will turn in favour of the new rulers which will be the previously suppressed working classes. To extinguish any memory or trace of yesteryear's cruelty the concept of private ownership, the root of all evil will be destroyed and then nobody will be able to deem themselves superior based on their status and priority.
For Marx and Engel this development is unavoidable and will happen regardless of how much the bourgeoisie tries to avoid it.The labour/working class will rise against the ruling class and this problem of inequality might need (at times a bloody) revolution rather than a mere set of slow reforms as the bourgeoisie will always be making excuses to divest the working classes of their rights and compensation aswell as their dignity.As they note in Part one "Bourgeois and Proletarians,"
The history of all hitherto existing society is the history of class struggles.