What is the difference between the member status "member" and "influenced when importing members for an acquisition program?

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What is the difference between the member status "member" and "influenced when importing members for an acquisition program?

Hi,

I'm importing members for an acquisition program and when I'm in step 3 "Import options" I have two types of member status: member and influenced. What is the difference between them? This contacts that I'm importing already downloaded a white paper from an online magazine's website where we made a campaign, not from our own website or form. This contacts are going to be used in our regional nurture campaigns. 

I hope you can help me,

Thanks!