如何从R中的因子变量中删除级别的排序？

The title says it all, I ordered a factor variable when I generated it, now I would like to remove the ordering and use it as an unordered factor variable. And another question, if I use my factor variable as a predictor in a regression does it make a difference to R if it is ordered (ordinal) or simple factor variable (categorical)?The title says it all, I ordered a factor varia