A numerical representation referring to a single unit or item.

एक

English Usage: "He has one cat."

Hindi Usage: "उसके पास एक बिल्ली है।"

Referring to a simple counting or a basic sequence.

एक, दो

English Usage: "She counted the steps

Hindi Usage: "उसने कदम गिनें

Referring to the first of a series; singular.

पहले

English Usage: "This is the one book you need to read."

Hindi Usage: "यह एक किताब है जो तुम्हें पढ़नी चाहिए।"

To perform an action in a sequence, often used in a rhythmic manner.

एक-दो करना

English Usage: "They began to one-two step to the music."

Hindi Usage: "वे संगीत पर एक-दो कदम करने लगे।"