Conversation so far:
What is Sequence?
Traditional Odissi repertoire sequence starts with an invocation called Mangalacharana.
What is the invocation?
A shloka (hymn) in praise of a God or Goddess.
What happens next?
The next sequential step in an Odissi performance is Batu.

Question: What is the Batu?
Self-contained rewrite: What is the Odissi Batu?