what's inadequacy between staticresource dynamicresource wpf?

when controlling resources such brushes, templates styles wpf, specified presumably staticresources

<rectangle fill="{staticresource mybrush}" />

or dynamicresource

<itemscontrol itemtemplate="{dynamicresource myitemtemplate}"  />

most times (always?), wholly works pitch difference during runtime. nonetheless i'd know why:

• what sure difference. memory opening implications


• are there manners wpf "brushes always static" "templates always dynamic" etc.?

i assume choice between stationary vs enterprising isn't erratic seems... nonetheless i destroy pattern.