Vaishnavas is a name for Brahmin community mainly from Karnataka, Andhra Pradesh, Tamil Nadu, Kerala and Maharashtra. They are the followers of Jagadguru Shri Madhvacharya who proposed the philosophy of [Dvaitha where Lord Vishnu is worshipped as Supreme God] by all Vaishnava Brahmins (popularly called Dvaitha) that preaches with the moto Hari Sarvottama - Vayu Jeevottama which explains Lord Vishnu as the Supreme power who is omni potent & omni present while all other Hindu Gods are his family. Vaishnavas are also called Madhwas because Madhvacharya was the first Saint to introduce Vaishnava Tattva (followers of Lord Vishnu as Supreme God) believe in Taratamya (Gradation theory) in all Living (jeeva) and Non-living entities (jada). Madhwas consider the Madhvacharya's 37 works coined as Sarvamoola as the most sacred literature that leads to Moksha.
Vaishnava Tattva was first introduced by Saint Madhvacharya also the word Madhwas were termed to identify the followers of Acharya Madhwa, in practice it has been generally referred to Vaishnava Brahmins following Madhvacharya's teaching. All Madhwas are Vaishnavas who believe in Vishnu as the supreme entity (Sarvottama), Vayu as the supreme living entity (Jeevottama) and all other devatas (Shiva, Parvathi, Ganga, Brahma, Saraswathi, Indra, Manmatha.) as the family of Lord Vishnu.
The Vaishnava Sampradaya mark two vertical lines with Gopichandana representing Lord Narayana's or Krishna's 'lotus feet'. In between a vertical black line is made from the daily coal of the dhupa (incense). In this sampradaya, worship is done to Narayana or Krishna daily. The coal left after offering incense is used to mark the black line. This is called as Angara. Underneath the black line, red dot is added to indicate that one has finished eating their lunch. This dot is called as Akshate.
Vaishnava or Madhwa men apply Dwadasha Namas - 12 vertical symbols over the body from Gopi-Chandana or Sandalwood paste offered to lord. Highlighted by angara-akshate (looks like an exclamation !) on their fore heads. While women generally apply kumkuma vertically aligned on their foreheads. Madhwas consider Gopichandana as sacred mud (mruttika), and is applied on the fore head, chest,shoulder & arms. Madhwas consider Tapta-Mudra dharana (hot-mudras) as sacred jewel for the body which burns all their sins. Mudras - Chakra & Shanka are dipped in charcoal fire and applied on the chest/arms.