What is the difference?
Comparisons
Half the naming problem is not "what is this called". It is "what is the difference between these two". Each page here settles one comparison with one decisive property, and one question you ask yourself.
ToastvsModal Dialog
If the user never saw this message, would anything break?
Full entryCheckboxvsSwitch / Toggle
If the user closed the page right now, would this choice already be saved?
Full entryCheckboxvsRadio Group
Would picking two at once ever make sense?
Full entryBadgevsChip / Tag
If you removed the thing beside it, would this still mean anything on its own?
Full entryAlertvsToast
Will the user need to read this message again a minute from now?
Full entryProgress Bar vs Spinner vs RingvsSkeleton
Do you know the shape of what is coming, or only that something is running?
Full entryCombobox / AutocompletevsDropdown / Select
Are there enough options that the user would rather type than scroll?
Full entryDrawer / Side PanelvsBottom Sheet
Is the screen wide, or is a thumb going to be doing the reaching?
Full entryTabsvsSteps / Stepper
Could the user legitimately start at the last item?
Full entryTabsvsAccordion
Does the user ever need two sections visible at the same moment?
Full entryBreadcrumbsvsSteps / Stepper
If you landed on this page straight from a search result, would the indicator still be correct?
Full entryTooltipvsDropdown / Select
Does the user need to move into what appeared and click something inside it?
Full entryAccordionvsDropdown / Select
Should the content stay visible while the user reads the rest of the page?
Full entry