wt's diffence between strong nucleophile and strong base?

Nucleophiles and bases and common reacting species in organic reactions.

A nucleophile is a reacting species which is electrons rich and attacks the positive-charged reaction site of the organic reactant.
For example, OH- ion in the following reaction acts as a nucleophile because it is electron rich and attacks the slightly positive-charged C atom to cause the reaction.
RCH2-Cl + OH- → RCH2-OH + Cl-
If attacking power of the attacking power towards the positive-charged reaction site is strong, it is a strong electrophile.

A base is a reacting species which eliminates an acid from the organic reactant.
OH- ion in the following reaction acts as a base because it elimination an acid HCl from the organic reactant. The HCl eliminated is then neutralized by the OH- to give H2O and Cl- (salt).
RCH2CH2Cl + OH- → RCH=CH2 + H2­O + Cl-
If its power of eliminating the acid is strong, it is a strong base.

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For small nucleophiles, the nucleophilic strength is usually approximately parallel to the basic strength. For example, ethanoxide ion (CH3CH2O-) is both a strong nucleophile and a strong base.

Bucky nucleophiles usually have weak nucleophilic strength. For example, dimethylethanoxide ion ((CH3)3CO-) is a strong base, but a weak nucleophile.
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usually strong nucleophile are strong base
i think u are talking about the elimination and Sn2
am i right?