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)
And somehow, we (stupid BLF’ers) still use kCd as an indication for throwers 
So does the surface area of the emitter affect Candela?
What is the meaning of “strenghth” in this picture? The words are spoiling it 
Yeh, I don’t like this picture analogy either.
Candela is how we measure throw (light direct from the light source at a given distance)
Lumens is total light.
Lux is how bright it is at a given point regardless of where the light is coming from.
How I would word it:
Lumens = Amount of light emitted in total.
Lux = Amount of light emitted on to a surface.
Candela = Amount of light emitted on to a point.
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)