What are differences between a pacifist and a conscientious objector?

During the First World War, when those who refused to be conscripted into the army hit the headlines, pacifism and conscientious objection became increasingly synonymous – especially in the English-speaking world, since it was only here that pacifism in the absolutist sense was sufficiently recognised for any kind of legal provision to be made for conscientious objection.

Explanation:

Pacifism’ was coined in 1901 (in French) to describe the ideas of the peace movement as a whole. It thus applied not only to the absolutist minority that unconditionally refused to fight, but also to the reformist mainstream, which believed that war could be abolished (for example, by improving international law and arbitrating disputes between states) but nonetheless accepted that, until such abolition was achieved, military force could legitimately be used for self-defence and enforcing international obligations.

ok so u have2 basically