Kriya Yoga is defined by three components

Tapas- Burning zeal or discipline in practice

Svadhyaya- self study

Ishvara Pranidhana- devotion to the lord                                                                                          These three practices work together: A bit of reflection will show clearly how the three principles (tapas, svadhyaya, ishvara pranidhana) work together. The principles are really familiar to us all, but seeing them clustered together as a single mode of spiritual practice is very useful. The mind can easily remember the three principles together as a single practice; it becomes a companion in daily life.