Verb
'ordenan' (infinitive ordenar)
1.Third-person plural (ellos, ellas, also used with ustedes?) present indicative form of ordenar.
2.(used formally in Spain) Second-person plural present indicative form of ordenar.
Never heard it used as a noun. Maybe it is 'ordinates', a.k.a. vertical axis. Still does not help clarify the question.
If you are referring to the different plots on a graph that represents the family of curves for a given number of poles then the different plots represent the degree of ripple allowed for the design, starting with Butterworth of zero ripple, then subsequent Chebishev designs with progressively more ripple in filter passband.
The greater the allowed ripple for a given number poles, the greater the skirt selectivity. At far out frequency all the designs eventually continue at 6 db per octave per pole rolloff (unless limited by physical implementation resulting in stray coupling around filter).
Hint, on practical side of filter design. Bessel (linear phase response) is an undercoupled filter. Butterworth (maximally flat) is critically coupled filter. Chebishev filters of more and more ripple are overcoupled filters.