Sharepoint team folders - Everyone except external users

Hi There, 

We have  set up some shared folders on sharepoint and given view/edit permissions to employees as relevant e.g. 'Ann & Barry' can view & edit the HR folder & files but only 'Ann' can view / edit the compliance folder / files. So why, under those folders am I now seeing 'everyone except external users' also has access? does this mean that everyone within the organisation can view these folders? 

Thanks,

Gemma