Pillar and Column are both vertical structures which are used to support significant structures or buildings like a house, staircase, etc. Although both pillar and Column are used for the same purpose, you will still notice some differences between them. A Pillar means any tall structure that is built vertically to give support to another large structure. A pillar can be made with metal, bricks, stones, etc.
Column, on the other hand, is a solid vertical structure built to support a larger structure above it, the larger structure above it can be roof or horizontal beam. Columns are mostly built with steel or masonry. Columns are mostly used to support larger structure, this is because they are made to withstand weight, while pillars are mostly used to support more prominent structure so that they can serve or look more of ornament structures. Another difference is that Column as a word has other different meanings apart from the one I have been explaining so far.