Final answer:
To list subdirectories starting with 's' without showing their contents or details, use the command 'ls -d s*' in a shell terminal.
Step-by-step explanation:
To see only the names of all the subdirectories of the current directory whose names begin with the letter s, the command you would type in a shell terminal is ls -d s*. The -d option tells ls to list directories themselves, not their contents. The s* is a shell pattern that matches any file or directory name starting with the letter s. This command will not show files within these subdirectories or any other details such as permissions, sizes, or modification dates.