Step 1: Recall the definition of sample space.
The sample space is the set of all possible outcomes of an experiment.
Step 2: Apply it to coin tossing.
When one coin is tossed, there are two possible outcomes:
- Head (H)
- Tail (T)
Step 3: Represent the sample space.
\[
S = \{H, T\}
\]
Step 4: Conclusion.
Thus, the sample space for tossing one coin consists of two outcomes — Head and Tail.
Final Answer:
\[
\boxed{S = \{H, T\}}
\]