What does it mean if a class is named something like this ".name.name2" and how to call it in HTML?

[cloudrockstar23727]

I’m currently working on the Pro Intensive project “MyTimes”, and one of the instructions tells me to create these classes:

.column.large {
width: 630px;
}

.column.medium {
width: 300px;
}

.column.small {
width: 240px;
}

[stetim94]

it means the element needs to have both classes, so for example:

<div class='column large'>i am affected</div>
<div class='column'>i am not affected</div>
<div class='large'>i am also not affected</div>

the .column.large selector would only target the first element/div. Not the remaining two, they have only 1 of the 2 classes, not both, as required by the css selector