The purpose of a conclusion paragraph is to remind the reader of the main point or thesis and to make connections to broader ideas or contexts. A conclusion paragraph should begin by restating and rewording the thesis statement (as stated in the final sentence of the introduction paragraph), then present the significance, relevance, or big idea of the thesis statement, and then should conclude with a closing statement. Where the introduction moves from a general idea to a specific idea, the conclusion paragraph begins specific and moves to the general.
Restated and reworded thesis statement
Remind the reader of the paper's main thesis by restating and rewording it from the beginning of the conclusion paragraph (in one sentence). This is more specific than what follows.
Significance
Usually in three-to-five sentences, describe the significance, relevance, or big idea that relates to the thesis. Make connections to other relevant contexts that apply to the thesis. Perhaps make predictions about future aspects related to the thesis statement. In most cases, this will be the only time you'll use the future tense in your paper.
Closing statement
The closing statement is the most general idea of the paragraph. It's the broadest statement that leaves the reader thinking about the thesis statement and overall text. Some writers choose a famous quote to conclude the paper but experiment with creating your own final saying, thought, etc. Try to come up with your own final quote that best applies to your paper.