Paracord is a kernmantle construction.
http://en.wikipedia.org/wiki/Kernmantle_rope
" constructed with its interior core (the kern) protected by a woven exterior sheath (mantle) designed to optimize strength, durability, and flexibility. The core fibers provide the tensile strength of the rope, while the sheath protects the core from abrasion during use."
"The braided sheath has a high number of interwoven strands for its size, giving it a relatively smooth texture. The all-nylon construction makes paracord fairly elastic; depending on the application this can be either an asset or a liability."
http://en.wikipedia.org/wiki/Parachute_cord
Dyneema is an Ultra High Molecular Weight Polyethelene
In climbing, cord and webbing made of combinations of UHMWPE and nylon yarn have gained popularity for their low weight and bulk, though, unlike their nylon counterparts, they exhibit very low elasticity, making them unsuitable for limiting forces in a fall. Also, low elasticity translates to low toughness. The fiber's very high lubricity leads to poor knot-holding ability, and has led to the recommendation to use the triple fisherman's knot rather than the traditional double fisherman's knot in 6mm UHMWPE core cord to avoid a particular failure mechanism of the double fisherman's, where first the sheath fails at the knot, then the core slips through.[14][15]
and
"In climbing, cord and webbing made of combinations of UHMWPE and nylon yarn have gained popularity for their low weight and bulk, though, unlike their nylon counterparts, they exhibit very low elasticity, making them unsuitable for limiting forces in a fall. Also, low elasticity translates to low toughness. The fiber's very high lubricity leads to poor knot-holding ability, and has led to the recommendation to use the triple fisherman's knot rather than the traditional double fisherman's knot in 6mm UHMWPE core cord to avoid a particular failure mechanism of the double fisherman's, where first the sheath fails at the knot, then the core slips through."
Climber's Accessory Cord is a strong dynamic rope.
" It is capable of use as a link in a safety chain designed to hold a fall. The rope must be protected against sharp edges or anything which could cut the internal or external fibres of the rope."
Basically it's another kernmantle rope, but comes in thicknesses from 2mm to 8mm, and in a wide range of colours.
Masses of information out there on the net, but most of it's on company websites and I haven't bought from them so I've just posted wiki links.
http://en.wikipedia.org/wiki/Rope
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