Before we discuss the three components of the data binding architecture, let's explain what is meant by the term binding. Simply put, a binding expresses the relationship between the data supplied by a data source object and the HTML consumer of the data. This relationship is called a binding because the value of the datem (short for data item) is synchronized between the client and the server. When an HTML consumer—for example, an HTML text box—modifies a datem, the modified datem is saved back to the data source object. Conversely, if the data source object changes the data value, the modified datem is sent to the data consumer. Generalizing further, multiple consumers can be bound to the same datem, and all values of all consumers are synchronized to the value supplied by the data source object. Values in the data source object are bound to the values in one or more data consumers.
Two distinct styles of binding are available: current record binding and repeated table binding. Current record binding uses HTML elements to display data from a single record from the data set—the current record. A different record can then be made current, in which case—the elements are updated dynamically to display the data from that record. Repeated table binding lets you specify a set of bound elements, called a template, that is repeated once for each record in the data set. Web authors also have the option of limiting the number of records repeated in the table, a feature known as table paging. Table paging and the two binding styles will be discussed in detail in the section "Building Basic Pages Using Data Binding" later in this chapter.