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.
