A picture is worth a thousands words! So for those trying to figure it out...
But if you despise pictures...
candela: intensity of a light source (similar to a unit of power like the watt)
lumen: the flux of photons (with an intensity given in candelas) passing through a given solid angle - e.g. a sphere around a candle (lumens = candelas x steradians)
lux: flux of photons passing through a given surface area (lumens per sq. meter)
To me that’s still not 100% clear. What’s the difference between a point and a surface? It doesn’t factor in distance for candela.
Lux = Light measured at a point/surface (the receiving area of a lux meter)
Candela = Light measured at a distance from the source (calculation of lux)