I launched spyder as was told to update to version 5.5.1 from 5.4.3 using:
conda update anaconda
conda install spyder=5.5.1
The 1st command above generated a flurry of output at the conda terminal prompt. This was in the base environment.
For the 2nd command, I used judgement to issue an update instead of an install because I didn't want confusion from the possibility of two versions installed: conda update conda. Furthermore, I did the update from the base environment as a test to see whether it propagates to my main working environment py39 (for Python 3.9). The 2nd command generated significantly less output at the conda terminal prompt, but I confirmed that Spyder got updated to 5.5.1 as expected.
When I activated py39, however, Spyder was still at 5.4.3. No problem, I thought, I'll just update Spyder in the py39 environment. After issuing conda update spyder, I was surprised to see much more output at the conda prompt. The only difference in what I did was that I did not issue conda update conda beforehand in the py39 environment.
Does this mean that issuing "conda update conda" in the base enviroinment only updates the base environment? If so, it changes my understanding of the command prefix conda, which I saw as a flag to identify commands to be interpreted by a layer that transcends all environments (even though the interpreter may choose to apply the command in the context of the prevailing environment). If the conda package can differ depending on the environment, then the designed-for behaviour of commands prefixed with conda can also differ.