Hahaha, I saw someone in the hallway wearing a contractor badge and a MIT hoodies. I am an alum so I asked about their time there. They said they graduated in 2003 but started in 91. I said, "Woah that's one helluva of a PHD." Turns out, they took a 10 year gap to play blackjack. Now they just work for fun every couple of years because they otherwise get bored.
Sounds like "casuals" vs. "contractors". Casual staff are often on very similar terms to contractors, apart from the rates of pay, but are seen as interchangeable rent-a-crowd rather than outside expertise.
There were casual workers at the last place I worked some had been there 20 year or more. One day (literally on one day) they were all told they were not needed, no severance, no thanks just let go. Disposable human workers.
The former are typically a group of second-class employees companies use as a way to "trial" someone before hiring them for real, or simply to skirt the requirements of employing someone full-time. They also tend to work for some shell company you've never heard of, at least on paper.
The latter tend to be older folks, and often experts in various fields. They also have little trouble finding another "gig" almost immediately after their current one dries up. These people are usually self-employed.
- Those who aren't good enough to get a full time job.
- Those who are too good to settle for a full time job.
The two groups are treated quite differently.