A review is given of the factors playing a role in particle adhesion and removal. The emphasis is put on those systems, which are of colloidal nature (so that gravitational effects can be neglected), and which are as close as possible to the sphere-plate model. It is shown that the major interaction forces are the omni-present van der Waals force of attraction and in an liquid environment, in addition, the electrostatic double layer force of repulsion and, in particularly in a polar liquid, the Lewis acid/base force of interaction, which is responsible for hydrophobic bonding. The magnitude of the various interactions depends on the surface properties of the adherents and on the deviations of the idealized model, such as an extended contact area. The latter is also responsible for alterations with time, either as a result of plastic or elastic deformation. The removal of particles of colloidal dimensions from a solid surface is controlled by the wall shear stress of the flow passing by, and in case of applying an air-liquid interface by the contact angle of the fluid and the adherents.