Tali ("clap") marks the stressed vibhags of a tala. Counting is physical in Hindustani music: sam takes the first clap, later talis are clapped and numbered, and khali takes a wave. Teentaal's pattern — clap, clap, wave, clap — is the reference example.
The tali/khali map is the tala's identity card. Jhaptaal (2+3+2+3) and Sooltaal (2+2+2+2+2) are both ten matras, but their claps fall in different places, so compositions built for one do not sit correctly in the other.