Asteya ('A' - not, 'steya' - steal) - one of the principles of material well-being. Asteya means not to take possession of things which belong to others. This means not to commit actual theft. Also stealing should not be done mentally. Those who want to steal but who refrain from doing so out of fear of being caught are ‘mentally’ stealing. Asteya means to refrain from both mental and physical stealing.
--- Four types of stealing ---
to take and take over the thing of the another person
to do not give what is due to others (e.g. not use taxi when it came to pick you up, use the service and not pay)
to desire to steal (in your thoughts) but without action (e.g. because of the fear of punishment)
to do not give what is due to others on mental level (allow the thoughts about stealing).
--- More deeper understanding --- If you spend your resources only for yourself and your family then all this sources becoming 'dark' or tamasic. So all traditions there is an idea that part of your incomes you should spend for good intentions (for people, for community..). Otherwise we allow our greed to control us. The basis of Asteya's violation is greediness, stinginess.
--- How to practice? --- Watch the mind. Always pay even for small things like public transport, pay your debts. Take care of the harmony and harmony will take care about you!
--- Definition --- https://www.yogapedia.com/definition/5539/asteya