A value list is like a lookup list because it displays a list of values in a drop-down list, except its list displays a list of options that you manually enter. A value list is useful if you enter the same data in a field again and again. For example, if you ship a product using three different courier services, you could create a value list that displays the three courier services, such as AirBorne, FedEx, and UPS.
Although it’s possible to change the options displayed in a value list, doing so is a rather cumbersome process. For that reason, you should only use value lists for values that will not change very often. If you want to display a lot of options, such as a list of state abbreviations, or values that may change frequently, you should create a table to store those values and then display them with a lookup list instead. It’s a lot easier to change values in a table than it is to change options in a value list
Here you can select to Allow Multiple Values. If you check this box, Access will allow you to select multiple values from your list and store them in a single field.