Values are simply things that we value ie like / give imporatance to.. For example we may value relationships, or money, or career, or comfort. They are all values.
Values can be major things such as Freedom, or than can be little things like ice cream.
Values are individual to each of us, whilst we may share some values we won't have all the same ones.
Things are valued to different levels for example I value my career to a different level to the importance that I place on having clean shoes. If I had to give one up it would be clean shoes.
Just because something is a value does not mean that we must take a specific action, for example I value spending christmas with the family but if something else came along that meant that I would ideally be somewhere else, then it could be ok to spend christmas away from them.
Values will guide our actions to some extent, typically if you are faced with two options and if option 1 fits your values more than option 2, then you will go with option 1.
Values are widely quoted in business along the lines of "these are the company values" at which point 5 or so buzz words will be quoted such honesty, value for money. It could well be that the company does value those things but they probably have a value attitude to a lot more than just those few things.
Values can be changed, some more easily than others, some with a greater impact than others.