This is the 18394th most frequent Russian word.
электричек
"Электричек" refers to suburban electric trains in Russia.
In this sentence, 'электричке' represents the mode of transportation, a suburban train, showing the instrumental case usage.
Я сегодня поеду на электричке до дачи.
I will take the suburban train to my summer house today.
Here, 'электричек' denotes a plural genitive case, referring to changes in the schedule of these trains.
Расписание электричек изменилось на этой неделе.
The schedule of suburban trains has changed this week.
'Электричек' here is used in the genitive plural to indicate the quantity of suburban trains served by the station.