Two positions in a sentence receive most attention, namely the initial and end positions. Thus, the new information that we want to convey to the readers should be placed at either one of these positions. The two choices create two types of sentences:

A loose (cumulative) sentence positions important information at the beginning of a sentence.

E.g., Plain language reforms become law in many countries because lawmakers believe that citizens should have access to documents they can understand.

A periodic sentence, on the contrary, positions the important information at the end.

E.g., Because lawmakers believe that citizens should have access to documents they can understand, plain language reforms become law in many countries.

Which type of sentence to choose depends on what you want to emphasize and the flow of your text. A general rule is to alternate between the two sentence types to create sentence variety and freshness.