Imagine the universe like a party. Relatively unknown guests at the party can pass quickly through the room unnoticed; more popular guests will attract groups of people (the Higgs bosons) who will then slow their movement through the room.
The speed of particles moving through the Higgs field works much in the same way. Certain particles will attract larger clusters of Higgs bosons – and the more Higgs bosons a particle attracts, the greater its mass will be.
This excerpt makes it a bit more understandable. Here’s the full article: What Is The Higgs Boson?