Shabbat is a day set apart by Jewish law (Halacha) from the working week. Family time and spiritual pursuits are emphasised and weekday activities associated with work are prohibited.
Our Jewish religious code spells out the Shabbat restrictions. For example, carrying and pushing wheelchairs and prams are only permitted in homes, private gardens and community areas. An Eruv is a boundary recognised by Jewish law, within which these activities are permitted.
According to Halacha, carrying on the Sabbath is prohibited and considered a desecration thereof. Most people who observe the Sabbath depend on the eruv in order to operate within a Halachic framework when carrying, using a pram etc.