Final answer:
A Linear layout displays a column or row of child widgets, commonly used in mobile and web development to arrange elements sequentially.
Step-by-step explanation:
A Linear layout displays a column or row of child widgets. This concept is particularly common in the development of mobile apps and websites. For example, in Android development, a LinearLayout can be used to create a single row or column which will contain child elements (or widgets), such as buttons, text fields, or images, in a sequential manner. Each widget will be placed in the layout depending on the orientation specified: vertical for a column or horizontal for a row. Similarly, in web development using HTML and CSS, a flex container with flex-direction set to row or column can serve a similar purpose.