This is a weed plant. It trails around the garden on bright pink stems, spurting forth tiny pink flowers and fragile looking leaves.
A weed is a wild, unwanted plant that infringes on other plants. Some weeds smother other plants, this one is just seen as wild, unseeded, unplanned. It is welcome in my garden though.
To me it is not a weed, I like to let a little wildness in. Too neat gardens hold less joy for me.
Do you prefer neat gardens, or something a little wilder?