【Exhibition】 , 【show】 ,  【exhibit】 ,  【exposition】 ,  【fair】  are comparable when meaning a public display of objects of interest.

【Exhibition】  and, less often in strictly formal use except in art circles,  【show】 are applicable to any such display of objects of art, manufacture, commerce, or agriculture or to a display (as by pupils, members, or associates) of prowess or skill (as in gymnastics, oratory, or music).

【Exhibit】  typically denotes an object or collection displayed by a single person, group, or organization in an  【exhibition】 , but in some uses it is not clearly distinct from  【exhibition】  or  【show】 , since the scope of an  【exhibit】  may vary from a single object to a collection coextensive with an 【exhibition】 ; thus, an artist might present a one- man  【show】  which would be at once an  【exhibition】  and an  【exhibit】  of his work.

【Exposition】 is the usual term for a very large 【exhibition】 , especially one involving the participation of many states and countries.

【Fair】  may be equivalent to  【exposition】 or it may apply to a small 【exhibition】 of wares, produce, or stock sometimes for the promotion of sales, sometimes in competition for prizes for excellence; it suggests a variety of kinds of display and entertainment and usually an outdoor setting.