Learn English – What’s the difference between ‘reliant’, ‘relying’ and ‘dependent’

Prerequisite - Co-requisite - Post-requisite -- Where task A is the prerequisite and task B can either be a co-requisite or post-requisite.

As a project manager I have often used predecessor/successor, but usually where there is a chronological order.

Project tasks are related in exactly the same way that some educational courses are. This does imply providing some sort of utility, but not necessarily and the relationship is well understood.

With this in mind, one of my college chem classes was a prerequisite and an associated chem lab was a co-requisite.

Historically there was no difference, and I suspect that is still so in some parts of the world. But in the British legal system at least there is a valuable difference, namely that juridical relates to the system of justice generally whereas judicial refers specifically to the acts of a judge. So if a judge says "You will go to jail for contempt" that is a judicial order; but there is a considerable amount of juridical paperwork to be completed.

You can, for example, buy books of precedents, and if they refer to court papers they are sometimes called juridical styles. But if a judge thinks the form is a bad one, there may be a footnote saying Judicially disapproved.