Is gascolator and fuel strainer the same thing?
Yes in practice they are the same thing (it's surprisingly difficult to find the origin of the term &quot;gascolator&quot;) and most definitions will mention both terms, although I tend to think of the gascolator part as the gravity water separator bowl/quick drain component, and the strainer as the filter screen covering the outlet.
Back when cars had them (up to the early 60s) they were called &quot;filter bowls&quot; with the bowl part made of glass and without the quick drain.  You just removed the bowl to get rid of any water you saw when checking under the hood (airplane gascolators from the 40s also used glass bowls, although most have been replaced by metal ones).
Most aircraft gascolators use a 75 micron mesh screen (the strainer part - about like the screen on those plunger coffee makers) at the top of the housing to keep particles from passing to the carb.  On my homebuilt I improved on that by using a 30 micron sintered bronze filter made for the filter bowl of a late 50s Chev Impala, which fits perfectly in the standard gascolator bowl.