Now, after so much time spent on this forum I don't know if you are being deliberately obtuse asking such a basic question but I'm going to answer it seriously.Yes, Polish is definitely closer to Czech than it is to Russian and closer to Slovak than it is to Ukrainian.
Sorry for ignorance,but some people on this forum including claimed naitive Polish speakers have different opinions on this regard.For example:
Moreover, Polish and Czech are very different due to historical reasons. Czech language as recreated in 19th century was deliberately made different from Polish so Czech people would not be afraid to lose their identity when neighboring with far larger Polish nation.
Polish and Russian have the same frequencies (if you analyse their spectra without looking at individual words, they are identical: that does not mean much in itself because that happens also with two uncorrelated languages such as Spanish and Greek). I speak Russian and right now I am in Poland and can understand quite a few things (I can even read newspapers!). Czech is also close to Polish, but I think to a lesser degree than Russian.
Thanks to my father in law, I now have Czech tv and radio. It sounds more like Russian and Serbo-Croatian than Polish does. It is decidedly weaker than Polish.
Maybe these posts a bit confusing but I do not know...
And from what I know Slovak should be much closer to Czech than to Polish and also have some unique traits.And Ukrainian is much closer to Polish than Russian.Especially in vocabulary.So I do not know what to think.