A programmer walks into a bar, checks his bank balance, checks his blood-alcohol level, checks his stomach capacity, checks the menu price, checks for bartender

A programmer walks into a bar, checks his bank balance, checks his blood-alcohol level, checks his stomach capacity, checks the menu price, checks for bartender availability, checks for open seating, and orders a beer. A tester walks into a bar and orders a beer. Then orders 0 beers. Then orders -1 beers. Then orders pi beers. Then orders 2.2 billion beers. Then orders 1 cerveza. Then orders an aircraft carrier. Then changes the programmer's beer order to 2 beers. Then cancels an order for a beer. Then flips the calendar back to 1980 and orders a beer. Then flips the calendar to 1925 and orders a beer. Then sets the clock to 23:59:45 and orders a beer.... Those bar jokes represent not only different skills, but different stereotypical personalities. The builder-programmer has to be cautious, methodical, and well structured, whereas the tester has to channel the spirit of the chaos monkey to find something that no one else ever expected.