House Entrance Doormat

Other uses:
a mouse mat is a small flat mat used to provide a flat surface on which a computer mouse can be operated. (A mouse employing a ball which is driven by friction and which drives a x and y movement sensors requires a regular flat surface with high enough friction to drive the ball. Older optical mice—typically those from Sun Microsystems—required a mouse mat with a differentially reflecting grid.)
an anti-vibration mat is a mat which performs the function isolating vibration between that which is above the mat and that which is below. Such a mat might typically be used when mounting a heavy machine which vibrates, onto a concrete floor; in the absence the anti-vibration mat, the machine tend to erode the floor through abrasion. Contrawise, some machines, such as the lithography machines used in chip fabs, need to be isolated from vibrations in their locale, and so are mounted on anti-vibration mats.
a slipmat is a circular piece slippery cloth or synthetic material designed to allow disc jockeys to turn or stop vinyl records on record players, or to scratch.