Firstly: Defining Prayer
Salah linguistically: is supplication.
Salah technically: worshipping Allah, exalted, by performing specific movements and actions and uttering specific statements, starting with takbirat al-ihram, and concluding with taslim.  Giving the salutations of peace – salam. In prayer it is the uttering of the salam to the right then the left to conclude it.
Secondly: The Prayer's Importance and Virtue
a) Prayer is the most important of Islam's pillars after the testimony of faith.
b) Allah has commanded it in all situations: as a traveller or resident, at war or in peace, and when healthy as well as sick.
c) It’s the Prophet’s ﷺ final reminder and advice for the Ummah.
d) It is from what has been legislated for all Prophets and Messengers.
e) Prayer is the pillar of the religion, and does not stand except by it.
f) The prayer is a deterrent from obscenity and wrongdoing.
g) It is an expiation from sins.
h) Abundant prayer is one of the reasons for proximity to the Prophet ﷺ in Paradise.