The answer to this can be different in different countries. This is because different countries have different welfare systems that attempt to help the poor (and even those who are not poor) in different ways.
The most typical way in which welfare attempts to improve standards of living is by giving money to the poor. The idea is that giving money to poor people will allow them to buy the things they need to have a better standard of living. Sometimes, welfare systems provide in-kind help as well. These systems will give poor people affordable housing or free medical care or money that can only be used to buy food. This is done to directly raise the poor people’s standard of living by providing them with things that they need.
Welfare systems will also try to improve standards of living by helping the poor gain more skills to allow them to get jobs (or get better jobs if they already have jobs). This can come in the form of work-training programs or educational programs. The idea behind this is to raise standards of living in the long term by helping the poor gain the tools they need to become wealthier.
Thus, welfare systems tend to try to raise standards of living in the short term by giving money and in-kind help and in the long term by providing education and training.