Deciphering the series and markings of Olympus cameras
It's no secret that there is a clear species hierarchy in the family of cameras. Simple digital compacts are located at the lower levels, and the highest echelons of power are represented by full-frame mirrors and mirrorless mirrors, or even delegates of a small detachment of medium format.
E, PEN (mirrorless)
Olympus was at the origin of mirrorless mirrors as a class. Their naming retained the philosophy of labeling film cameras with interchangeable optics. So, the brand's mirrorless cameras are divided into two major categories:
OM-D (top grade with Micro 4/3 matrix) — the family includes four generations of models of advanced amateur level E-M10, three generations of semi-professional E-M5 and three versions of top mirrorless E-M1;
Unfortunately, the future of Olympus mirrorless mirrors seems very vague.
TOUGH (all-protected compacts)
Unkillable compacts under the Olympus brand mark are assigned to the TOUGH dust- and moisture-proof cameras squad.
μ (low-cost compacts)
The "mu" category includes the simplest of Olympus cameras. Their key advantage is a tasty value. The cameras of the mk series do not have serious photographic ambitions.
That's it. Have a good shooting!