Indicators are something which Indicates us something.Acid base indicators tell us that whether the substance is an acid or base by changing colours.Like litmus, purple cabbage etc,.
Indicators are chemical substances which is used to indicate the given chemicals as acids or bases

Indicator r those substance which tells us that given sample is acid or base by changing its colour .
Indicators are the substances which helps us to know the colour or structure of a chemical compound. Indicators are of two types – Natural indicators and synthetic indicators.