The Samskaras is a series of rituals that mark the various stages (milestones) in a Human life, as per the Sanatana; and they need to be celebrated.
They are performed in 5 different stages of a human life :-
Stage 1: The prenatal years,
Stage 2: The childhood years,
Stage 3: The student years,
Stage 4: The adulthood years and
Stage 5: The old age years.
In Vedas there are 40 samskaras prescribed, out of which 16 (called the Shodasha samskaras) are in practice even today; as produced below :
1. Garbhadhan - Conception
2. Pumsavana - Foetus Protection
3. Simantonayana - Satisfying wishes of a pregnant woman
4. Jatakarma - Birth Rituals
5. Namakarana - Child Naming Ceremony
6. Nishkramana - Child’s first view of the Sun/Taking the child outdoors for the first time
7. Annaprashana - First feeding of solid food to the child
8. Chudakarana - First tonsure of the child's head (boys)
9. Karnavedha - Ear Piercing (for girls)
10. (a) Upanayana - 'Upa' means 'near' and 'nayana' means 'to take to'; hence taking the child to a teacher.
(b) Vedarambha - Beginning the Study of Vedas and Scriptures
11. Keshanta - Hairs are cut, guru dakshina is given.
12. Samavartana - Completing Education/Returning home from the Gurukul
13. Vivah - The Marriage
14. Vanaprastha - Retirement/Preparing For Renouncing
15. Sanyasa - Renunciation/Attaining Nirvana and Enlightenment.
16. Antyeshti - Last Rites for the dead/Funeral rites.
These samskaras are meant to cultivate positive qualities to purify the soul and ultimately lead it to Realization!
The whole life process is beautifully encapsulated in the above 16 rituals for us to follow.