What does it mean when my truck sputters when I accelerate?

Probably needs a tune up. plug wires, spark plugs, distributor cap and rotor. Also change the air filter and fuel filter and crank case filter as well as PCV valve (positive crankcase ventilation valve) this valve scavenges harmful acid deposits or blow by and reburns it and sends it out the exhaust pipe. Examine everything before you buy new if the plugs look good just reset the gap if the wires look good move on to the cap and rotor. you can find images on the internet to look at to compare condition of most parts at least just by look. if that does not do the trick you may have to take it to a mechanic. be sure you tell them all you have done. start with plugs cap and rotor then fuel filter. Check the air filter if you cannot see light through the paper element replace it for sure. the sputter can indicate not enough fuel or insufficient spark to ignite the fuel.
spark plugs can do wonders if they have not been changed for a long time. the fuel/combustion deposits rob the spark from jumping the gap which ignites the fuel under higher cylinder pressures. when the spark travels directly to ground without jumping the gap the cylinder makes no power.