led, LED

Led or led ( rhymes with head ) is the past tense of "lead" ( rhymes with bead ), meaning to direct or to go in advance of--
"Seventy-six trombones led the big parade..."
The captain led his troops into battle.

LED ( always capitalized, "ell ee dee" ) stands for "light-emitting diode"--
An LED looks like a miniature light bulb.
Your digital display may be an example of an LED.

Now that you know that, you can say--
"The invention of the LED led to the development of a low-energy light bulb for home use."

Note--"lead" may also mean the metal or element ( pronounced to rhyme with head )--
Lead protects Superman from kryptonite.
The dentist puts an apron full of lead pellets on patients before an x-ray.
Note # 2--"LCD" ( ell cee dee ) stands for "liquid crystal display"--
New TV's usually have an LCD screen.

lead, led, lead

Led or led ( rhymes with head) is the past tense (yesterday, or some time ago) form of "lead" ( rhymes with seed)--meaning to go before, show the way, or take charge--
He led the troops into battle.
The conductor led the orchestra.
Some people are not easily led.

Lead or lead is considered to be two words--
 The first ( rhymes with seed ) means to go before or show the way--
Lead the way!
"...and a little child shall lead them..."
The second ( rhymes with head ) means the metal used as a weight or at one time in pencils or for bullets--
In the western movie, the bad guy threatened to plug the hero full of lead.
People once made their own lead pencils.
Lead may be used to make weights.

Now that you know that you can say--
"The lieutenant led them into a rain of lead bullets."

Note--kryptonite is pretend, lead ( the metal ) is real--
Superman uses lead as a shield to protect him from kryptonite.
The dentists puts a lead apron on patients to protect them from radiation.