Here's my understanding of these Poor Law terms :-

"Relief" for those too ill or old to work, the so called deserving poor, was in the form of a payment or items of food ('the parish loaf') or clothing.

"pauper" - someone in receipt of Relief administered under the poor law .

"indoor pauper " - someone would lived in the Workhouse

"outdoor pauper " - someone would lived elsewhere, but supported by Relief {sometimes seen as Outdoor relief}