They were the standard form of lighting long time for many photographers, especially for portrait work.
There was not much behind them, other that they were quite powerfull by wattage and run at over-voltage to different degree, resulting in higher colour temperature and extreme reduced life expectency. The were available in omnidirectional form to be used in a reflector, or with built-in reflector to be used on their own. They werfe expensive (compared to household lamps) and thus often used in special circuits that allowed them to be run at undervoltage to soare them during light-fall checking and were ony run a nominal voltage for metering or actual taking.
Otherwise they were plain incandescant lamps.
Floodlights typically designate halogen tubes.
In case you refer with "too strong for an appartment" to the electrical circuit:
You must got something wrong.
A typical toaster today has 1000W, a hairdryer up to 2000W. If 500W would be too much for an installation than many classic electrical devices already would have done so before. Or with other words having a light bulb on and making a tea with even a plain, old-style dip-in heater would be at the verge.
But yes, a complicated still lightng outfit could stress an circuit, but more so a Super-8 cine lighting with 3 floodlights already as at the verge of nets over here.