@rivorson is correct in his description. Express consent is where you take an action to indicate consent to the company. As compared to implied consent where you may not have to given specific consent
To express means to manifest in some way. So for example they will ask for consent to execute orders in line with their policy and you say ‘yes I consent’
Implied consent may be someone just assuming because you were in the building you were consenting to something new without your affirmative expressed consent.
Good question