1. Svar/s (Vowels)
In Indian scripts, most vowels have two forms - independent & dependent.
Vowels in the beginning of words are written as 'independent letters'.
Vowels within words are mostly written as signs over previous consonants hence are called 'dependent vowels' or māŧrāEn̐. We will discuss them later.
An independent vowel is called svar (स्वर; swar). The svar/s are arranged at the beginning of the Varṇamālā (ĐevaNāgarī alphabet).
These vowels were arranged according to a scheme. This scheme is largely phonetic and helpful in memorizing & reciting these vowels.
‘आ’ (AA or Ā) is considered as long form of the vowel ‘अ’ ('A') but it is another short vowel. ‘ऐ’ ('AI' or 'AY') is a diphthong (combination of two vowels) containing ‘ए’ ('E'). ‘औ’ ('AO' or 'AU') is a diphthong containing ‘ओ’ ('O').
‘ऋ’ is considered a vowel but it is not a pure vowel. Its pronunciation might have been like a semivowel! The common (modern) pronunciation of this is 'Ṛi' in Hinđī and Sanskṛiŧ. It is pronounced as 'Ṛu' in Marāthī.
We can consider it (ऋ) as a consonant-vowel conjunct.