Sidereal zodiac
Sidereal zodiacs place twelve 30° signs using a stellar reference. An ayanamsa specifies their relationship to tropical positions.
How it is defined
Different ayanamsas can give different results near boundaries. These signs also differ from astronomical constellations, whose extents are unequal.
How to read it
Symbols work in combination: a sign modifies a function and belongs to an element and modality. That combination provides more context than an isolated label.
A concrete example
Before comparing sidereal signs, confirm that both calculations use the same ayanamsa and date. Merely describing both as sidereal is insufficient.
Explore further
Compare Sun, Moon and ascendant within one chart. Identify which factor you are reading before applying a general description to your own situation.