Patanjali Yoga Sutra — क्षणप्रतियोगी परिणामापरान्तनिर्ग्राह्यः क्रमः ॥4.33॥
Kṣaṇapratiyogī pariṇāmāparāntanirgrāhyaḥ kramaḥ॥

‘Krama’ is the moment by moment, series of subtlest mutations (changes) happening in an orderly way, but perceivable distinctly only at the end of sequence owing to the smallest changes taking place every moment.
The change could mean and include:
- Jāyate: Dawn, birth, coming into existence
- Asti: Existence
- Vardhate: Development, growth, escalation
- Vipariṇamate: Change, modify, transform, mutate
- Apakṣīyate or kṣīyate: Decay, decline, descent, decrease, diminish
- Mriyate: Death, dissolution, seemingly cease to exist.
Yes, everything in this universe is subject to these six changes. Everything is subject to all the above said different phases of changes. Change is the only permanent phenomenon. The continents move slowly, planets change gradually; stars alter their nature bit by bit. New galaxies are forming and existing ones are vanishing!!! The universe is full of never-ending activities. Patañjali describes how slow the mutation or transformation is, in this aphorism.
So does the life of a man. Take the example of a baby. Baby grows every moment. But the growth is so small that, it is not recognizable every moment. That is the reason why parents who are always with the baby would fail to perceive the baby’s growth. But guests rarely visiting our houses would exclaim ‘Wow! As compared to our last visit, your baby has grown a lot’! That means the change is perceivable only after a reasonable length of time or at the end of a stage.
Bhagavān describes the inevitable impermanence in the objective world thus:
देहिनोऽस्मिन्यथा देहे कौमारं यौवनं जरा।
तथा देहान्तरप्राप्तिर्धीरस्तत्र न मुह्यति॥गीता २.१३॥
जातस्य हि धृवो मृत्युर्ध्रुवं जन्म मृतस्य च।
तस्मादपरिहार्येऽर्थे न त्वं शोचितुमर्हसि॥गीता २.२७॥
dehino’smin yathā dehe kaumāraṁ yauvanaṁ jarā।
tathā dehāntaraprāptirdhīrastatra na muhyati॥Gītā 2.13॥
jātasya hi dhruvo mṛtyurdhruvaṁ janma mṛtasya ca।
tasmādaparihārye’rthe na tvaṁ śocitumarhasi॥Gītā 2.27॥
Just as having a childhood, youth and old age as different phases in life, the undying jīvātma is subject to change-over to another body (every time he loses his body). Hence, this should not mislead sensible men. Because, death of the physical body is inevitable to the one born, and birth is certain for the dead. Thus, there is no rationality for lamenting these unavoidable phases.