From Phonebloks:

A phone only lasts a couple of years before it breaks or becomes obsolete. Although it’s often just one part which killed it we throw everything away since it’s almost impossible to repair or upgrade.

Phoneblok is made of detachable bloks. The bloks are connected to the base which locks everything together into a solid phone. If a blok breaks you can easily replace it; if it’s getting old just upgrade.

It’s like an app store for hardware. In the store you buy your bloks, read reviews and sell old bloks. Small and big companies develop and sell their bloks. You can buy a pre-assembled phone or assemble it yourself by selecting the brands you want to support. The choice is yours.

Source: Phonebloks