# What is the optimum design: elliptical lift distribution or elliptical span loading parameter distribution?

I am getting very confused with these terms. I'm trying to analyse a span loading distribution given as cl(y)c(y)/ccL. This distribution is almost elliptical but when I plot just cl(y) it changes and I have more cl near the tips due to the reduction in chord.

This made sense from my point how view since the AR is low, the sweep is high and the taper ratio is small. It is like the figures I remember for these cases. However, when I have searched in google I have seen this image: This wing is pretty similar to mine, and the distribution is similar to my cl(y) distribution. However, the parameter here is cl(y)c(y)/ccL!!

I don't understand completely the difference. When we talk about elliptical distribution for minimum induced drag it is about cl(y) or cl(y)c(y)/ccL? Why is this parameter used and plot and not cl(y)?

Minimum induced drag is reached when the circulation distribution over span is elliptical. Circulation is indeed proportional to the product of the local lift coefficient and the local chord (c$_l \cdot$c). The diagram in your question normalizes this with the overall lift coefficient c$_L$ and the mean chord $\overline{\text{c}}$.