what do the continuous and categorical type options on the x-axis format section mean?

hi all,

i am trying to learn more about power bi desktop. i created a stacked column chart.

in the x-axis section there is a field named "type". it has 2 options continuous and categorical.

i selected each option and the only thing i noticed was that the width of the columns changed.

i searched this forum, but couldn't find anything that explained these options.

i searched for an explaination of these options. the only page i found was this one, but it doesn't say what the options should be used for. it just says to select one or the other . . . duh!

https://powerbi.microsoft.com/en-us/documentation/powerbi-service-tutorial-customize-x-axis-and-y-axis-properties/

i'd like to know if someone can give me a short description of what these options are for or what they mean of when to pick one over the other.

any help would be greatly appreciated.

thank you

tracy