A can is subjected to compression force.

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Compression is a force applied to the outside of an object that pushes inward or toward the object’s center. Have you ever used an aluminum can crusher? When using a can crusher, you’re applying a compression force to the can. While under compression, the can’s sides buckle, and the can collapses.

Tension can be described as a pulling or stretching force. The two teams in a game of tug-of-war are exerting tension force on the rope.

Some materials withstand tension, but not compression. Some are just the opposite. Ropes are great for tension, but aren’t rigid, so they’re unable to resist compression. Wood, however, has good compression strength, but sometimes snaps under tension.

A structure, as a whole, must resist buckling under compression and snapping under tension.