CR — lithium coin
Usually 3V. Common in trackers, bike sensors, calculators and remotes (CR2032, CR2025, CR2016).
Do not mix with 1.5V alkaline button batteries of a similar size.
LR — alkaline button
Usually 1.5V. Common in calculators and toys (LR44, LR41).
Cheaper and shorter-lived than silver oxide of the same size.
SR — silver oxide
Usually 1.55V with a steadier voltage — preferred for watches and precise devices.
SR44 is the same size family as LR44 but a different type — check the device manual.