Will the Apple Watch accessories for the 38mm fit the Apple Watch 4?

Will the 38mm accessories fit the 40mm accessories for the Apple watches? Kinda like how 7+ things fit the 8+ things with the iPhones etc

I was wondering because I just recently purchased my first Apple Watch, series 4, the Nike edition, 40mm & when I type in accessories for that online most things pop up as 38mm/40mm, so I was just wondering before I make any purchases for accessories…

All the watch bands since the original will fit both sizes of series 4 watches.

The bands for 38 will fit 40, and 42 will fit 44. The watches themselves aren't that different in size but the display is bigger. The types of band or case that snap over the entire watch won't work though.