A faint click or total silence when the starter key is turned usually means that the battery is almost or completely flat. If, however, the battery is fully charged, the trouble is probably in the circuit between the battery and starter.
Frequent short trips, with constant stopping and starting, make your
battery work very hard, especially in winter when heater, headlights, heated windows and wipers may be working most of the time.
If your car's instrument panel includes an ammeter, it will tell you how well the charging system is working - the difference between the charge going into the battery and the power being used from it.