so everything is good.
SMART overall-health self-assessment test result: PASSED
The important column is VALUE. It will get lower if there is a problem. THRESH is the threshold where the value is considered bad. The RAW value is sometimes in useful units, but not necessarily.
ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE
1 Raw_Read_Error_Rate 0x002f 200 200 051 Pre-fail Always - 0
3 Spin_Up_Time 0x0027 177 177 021 Pre-fail Always - 4141
194 Temperature_Celsius 0x0022 108 098 000 Old_age Always - 39
So for Raw_Read_Error_Rate, VALUE is a much bigger number than THRESH, so you are fine. In fact given that RAW is 0 there probably have never been any read errors. But you may find that some manufactures pack extra info into the raw value, like how many total reads there have been, so that could be non zero and still fine.
Spin_Up_Time is probably an actual measurement, so 4141 might mean 4.141 seconds. but it could also be different units or a set of flag values. either way VALUE is still high so everything is fine.
Temperature_Celsius, here the raw value looks like its probably in degrees C. 108 is big enough that its not an issue. the hottest the drive ever got scored 098, so its been a little bit warm than 39C at some point in its life. still not an issue.
someone (maybe you) ran a couple of extended tests, and the drive was fine.
SMART Self-test log structure revision number 1
Num Test_Description Status Remaining LifeTime(hours) LBA_of_first_error
# 1 Extended offline Completed without error 00% 28 -
# 2 Extended offline Completed without error 00% 3 -
https://en.wikipedia.org/wiki/S.M.A.R.T. has info about many attributes and is worth a read if one of them starts to go bad.