The word "tzaddik", typically translated as "righteous", comes up quite a lot in different Jewish texts. Someone who is righteous would be called a "tzaddik", as a noun. There are often different levels of righteousness, which I am here referring to as the "righteousness hierarchy", for lack of a better term. Generally, this refers to multiple gradations of being a tzaddik, or some level beyond that of a tzaddik. More "normal" people would be either a rasha (wicked) or beinoni (in between).
There is a lot of variation in what exactly the term means, however, depending on the source. For instance, the Talmud (I have no specific page number, but this is what I understand the Talmud to say by other sources) states that a tzaddik is anyone whose good deeds outweigh their bad, and so is written in Sefer Tzaddikim on Rosh Hashanah. The Tanya's first chapter, meanwhile, states that a tzaddik is far above such a level, and in fact not only has no sins, but has no desire to sin at all (and, if I understand the text correctly, may not even have any evil inclination!). The beinoni, meanwhile, has no sins but may still have a desire to do so, that must be overcome. The Tanya explains that the Talmud uses the concept of a "relative tzaddik" when discussing the idea, and does not, as far as I know, discuss any level or gradation above that of the tzaddik. It also says that people are either born with this capability (or at least potential for it), or they are not and so the beinoni is the highest achievable ranking for most.
Mesilas Yesharim, by Rabbi Moshe Chaim Luzzatto, gives a gradation of yeshar < tzaddik < chasid < kodesh, where the first three are attainable by anyone through their own merit but the kodesh requires intervention from Hashem. I am not certain whether all four levels are in fact "tzaddikim" (that is, the whole concept has the name of its second level) or if only the second level is. Meanwhile, one footnote to the Koren NCSY Siddur for weekday and shabbos (page 423) quotes another rabbi, Rabbi Chayyim of Volozhin, who places the yeshar's status above that of the tzaddik, and says the tzaddik retains a desire to sin and the yeshar does not. In this formulation, the tzaddik is like that of the Tanya's beinoni, and the yeshar is like the Tanya's tzaddik. (Information is not given as to if or how a normal person can attain these levels).
There are enough commonalities between these different ideas that it seems as though they might be talking about the same phenomenon and simply disagree on the nomenclature, but there are also some notable differences. What exactly are the relationships between the concepts of tzaddik, beinoni, chasid, etc, within these different fromeworks? Do they refer to the same thing but with different words? Are they related but distinct ideas? Or do the sources disagree on what it means to be a tzaddik in a more fundamental way than simply what word refers to what status?