shodomon - Gateway of the Holy Path
nangyodo - Difficult Path
jiriki - Self Power
-the Gateway of the Holy Path is understood to be the traditional practices of meditation and precepts by which the ascetic attains enlightenment by their own means through great effort.
jodomon - Gateway of the Pure Land
igyodo - Easy Path
tariki - Other Power
-the Gateway of the Pure Land is for those who lack discipline and proper instruction and entrust their salvation to the Other Power of the various cosmic buddhas and bodhisattvas.
zogyo - Miscellaneous Practices (related to pure lands other than Amida's)
shogyo - Right Practices (related to Amida's Pure Land)
jogo - Auxiliary Practices are the four Right Practices of: 1) reading and reciting sutras, 2) contemplation, 3) doing prostration, 4) giving praises and offerings.
shojo-no-go - Rightly Established Practice is the one Right Practice of uttering the nembutsu. This is senju-nembutsu, the exclusive or single minded recitation of the nembutsu
ketsujo-ojoshin - Firm Establishment of Faith which assures Birth in the Pure Land
irui-no-jogo - Different Good Practices are all the Miscellaneous Practices which, after the Firm Establishment of Faith, correspond to and support the single practice of the nembutsu.
ojo - Birth [in the Pure Land]
nehan - nirvana is final enlightenment in Buddhism and is achieved after Birth in the Pure Land where one can properly study and accomplish the practices of the Holy Path.
For a detailed explanation of this process of Senchaku