Soldiers line up, spaced with pride, Two long rows lined side by side, One sole unit can decide, If the rows will unite or divide. What am I?

Answer: A zipper.

More What am I ? with answers

More What am I ?

Some people avoid me, some people count me, some people just consume me. What am I?
Some people believe in me and others don’t at night I roam around and sometimes I float. If you hear a troubled noise coming from the ground go run and hide from my creepy sound. What am I?
Sometimes dark and sometimes bright, I make my way among twinkling lights. Seas and oceans obey my call, yet mountains I cannot move at all. My face is marred and gray, but I’m majestic anyway. What am I?
Sometimes I am light, sometimes I am dark. Most people like me. What am I?
Sometimes I am light, sometimes I am dark. What am I?
Sometimes I am liked, sometimes I am hated. Usually I am old, usually I am dated. What am I?
Sometimes I fly as fast as the speed of light. Sometime I crawl as slow as a snail. Unknown until I am measured but you will certainly miss me when I’m gone. What am I?
Sometimes I shine, sometimes I’m dull, sometimes I am big, and sometimes I am small. I can be pointy, I can be curved, and don’t ask me questions because even though I’m sharp, I’m not smart enough to answer you. What am I?
Step on me and you'll reach the top first, but step under me and you're cursed. What am I?
Stolen from a cow, I'm placed in a vat. My flavor gets stronger the longer I've sat. What am I?
Sweet, sour, tart, and sugary, you can see me in every store and in every pantry. What am I?
Swifter than the fastest horse, through four rooms I run my course. I appear crimson in the light, but blue is what I am at night. What am I?