In this article, we will cover how the setting you see below for respectively the Chrome Plugin and the Dashboard influences your attribution data.
Chrome Plugin  | Dashboard  |
Simply put: A channel that is checked is included in the attribution while an unchecked one isn't included in the attribution. An included channel gets credit for an order while an excluded one doesn't receive credit (if other channel(s) were part of that customer journey).
To illustrate how this affects your data let's have a look at a customer journey where you see the First and Last Click marked:
This is a customer journey where all touchpoints (channels) are included
Now let's have a look at how the attribution of First and Last Click changes if we exclude Google from the attribution (deselecting Google from the touchpoint selection) in this customer journey.
This is the same customer journey from above but with Google Ads touchpoints excluded
What now happened is that all Google Ads touchpoints users had are not being considered in the attribution. Therefore Google Ads doesn't get any credit for orders where other channels were involved and the Last Click attribution in that customer journey from above shifts to Influencer. The other channels in this scenario get more credit for the order if we look at Linear attribution.