keywords in ER diagram description

[Snowden FU]

I am confusing about the keywords "can only have one xxx" and "have exactly one xxx", do they have the same meaning?

here I give a example in Practice 01: a team can conduct only one order

does it have the same meaning with a team conduct only exactly one order?

[Yu Hao]

Hi,

Personally, I think that

can conduct only one means 0 or 1

conduct only exactly one means 1.

For example:

 a team can conduct only one order =  a team can have 0 or 1 order.
a team conducts only exactly one order = a team has 1 order.