"It is a game."
Translation:यह एक खेल है।
खेल is both a noun and a verb like the English words 'cook', 'offer' etc.
The noun खेल means 'game' or 'sport'.
खेल is also the stem of the verb खेलना ('to play'). 'खेलता' is its masculine simple present tense form, 'खेलती' is the feminine simple present tense form, 'खेल रही' is the feminine present continuous form and so on.
So, 'वह खेलती है।' is 'She plays' and 'मैं एक खेल खेल रहा हूं ।' is 'I am playing a game'.