A pillar is a synonym for column, or an upright post that usually holds a structure up. A pillar is usually part of a building's structure, whereas a column may be decorative.
I would like to turn the basement into a party area for guests, but there are too many pillars in the middle of the room. I cannot take them out because the whole house rests on them.
Alex loves holidaying in Turkey, but thinks looking at the Greek ruins there is boring. He says that all you can see are old, broken pillars. The buildings the pillars used to support aren't even there anymore.
Figuratively, we can use pillar to describe a very important part of something or member of a group. For example, we often speak of a very active, respectable person as a pillar of society. Or the five most fundamental beliefs in a religion, for instance the Islam, are called the Five Pillars of Islam.
Your cousin Dave is a volunteer firefighter and just got promoted to head teacher at his school. He also used to serve on the city council. He's a real pillar of society! I don't know where our town would be without him, really.
A frame is the basic, underlying structure that gives something its shape or strength. We usually use it in this sense to talk about the frame of a building, but can also talk about a human or animal's body structure or general build.
Our apartment complex is still under construction. There are pillars, beams, floors and ceilings, but no walls. Basically, the frame is up but not the rest.
Sally has a really small frame. Her shoulders are close together, she is short, and her hips are quite thin. She looks like she could blow away in the wind!
We also use frame to talk about the hard case around a picture or painting. We can use the verb frame to describe the process of putting a picture or painting into such a case or a frame.
Look at that beautiful frame around the Picasso painting there! It has carved wood and is painted very delicately. It's almost as impressive as the painting that it surrounds.
Sandra got me a beautiful birthday present. She printed an old photograph of us as kids and then framed it, so I can hang it on the wall.