In pranayam (प्राणायाम), we follow the breath cycle which is Puraka, Kumbhaka and Rechaka.
Puraka(पूरक)
The Sanskrit term puraka (पूरक) means the inhalation or breathing in through the nostrils slowly.
Kumbhaka (कुम्भक)
The Sanskrit term kumbhaka (कुम्भक) means holding the breath. There are two main types of kumbhaka in pranayam practice , antara kumbhaka (अन्तर कुम्भक) and bahya kumbhaka (बाह्य कुम्भक). Aantara kumbhaka (अन्तर कुम्भक) means holding the breath after inhalation and bahya kumbhaka (बाह्य कुम्भक) means holding the breath after exhalation.
Sahita Kumbhaka (सहित कुम्भक) and kevala kumbhaka (केवल कुम्भक) are other types of kumbhaka.
Sahita Kumbhaka (सहित कुम्भक) is further divided into sagarbha kumbhaka (सगर्भ कुम्भक) meaning with mantra and Nigarbha kumbhaka (निगर्भ कुम्भक) without mantra.
Rechak (रेचक)
The Sanskrit term rechak (रेचक) means releasing the breath gradually and slowly.
Note:
People with any heart conditions or high blood pressure should practice pranayam under the guidance of a professional.