This remains a frequent question that a lot of beginners tend to ask. The confusion is as genuine as it can get. Another version of the same question is an electric better than an acoustic. Acoustic guitars also come with electronics, often called as semi-acoustic or electro-acoustic (same thing, different names). So Let us first figure out the types first.
1. Acoustic Guitar: A 6 string guitar that will be hollow inside and does not have any electronics attached to it. There will be a sound hole that helps the sound resonate. If you want to perform with this guitar you cannot since it does not have the electronics. However recording in a studio can be done by micing the Guitar.
2. Semi-acoustic / Electro-Acoustic: A 6 string acoustic guitar that has electronics (pickup) makes it an Electro Acoustic / Semi Acoustic. Piezo is the most common pickup with a wire under the saddle. There are some pickups with Equalizers and Tuners and some with just a tone and Volume. They are usually battery powered with a 9V battery. Can be used to perform live and for recording purposes.
3. Electric Guitar: A 6 string guitar that is usually a solid body and has electronics. There are semi hollow body electric guitars as well, but that is counted under an Electric Guitar. Unlike the above two, electric guitars cannot be played without an amplifier. These guitars are mounted with magnetic pickups that produce sound once plugged in.
Now which should a Beginner buy?
Ideally I would NOT recommend an electric guitar to a beginner. The primary reason is that a beginner should know a guitars natural sound without it being produced from an amplifier. The second reason is that an electric guitar needs a higher control to play and as a beginner you should rather get your focus on theory and coordination between both your hands. Often there is a misunderstanding that the electric guitar is at a higher level than the acoustic. Many students even assume an electric guitar as a graduation from the acoustic schooling. However this is not true in any manner. Both are individually very different sounding instruments and are NOT superior to each other. A practical suggestion is to spend time with an acoustic as much as you can and then venture out to the electric guitar if it interests you. With that being said, you can also play the acoustic FOREVER and explore that never ending journey as well.
Now we land to the second question. Should a Beginner buy an Acoustic or Electro Acoustic?
Now this depends on one factor primarily. If you have NO plans to perform on stage and just want to do this as a hobby, you should avoid the electro-acoustic. An acoustic guitar should be more than enough for hobby playing. Ideally as a beginner, you don’t really need to plug the guitar into an amp for home practice. And even if you decide on performing later or adding effects to your guitar, you can always get a pickup installed at a trusted music store / luthier. There is no difference between factory installed pickups and one that is installed later. Even in factories, the body is cut after the whole process and the similar will be done by a Luthier as well.
Now if cutting the guitar body scares the living light out of you, Magnetic pickups are a good option to go for. They are easy to install on the sound hole and gives a good quality sound without much feedback like the piezo. Plus, it has rechargeable battery unlike the 9V. You can check out for magnetic pickups from a brand called Double that is now available in India. Great Option!
On the other end, if you would like to perform in the near future at local cafes, school, college etc. you should consider buying the electro acoustic. It will be a onetime investment and has no downsides to it. We have been asked many a times if the acoustic sounded better than the electro acoustic of the same model and brand, and the answer is NO. Also if you are assuming the Electro Acoustic will do Electric Guitars job or vice versa, the answer is again NO. Electro-Acoustics are meant to amplify the acoustic guitars sound and not make it sound like an electric guitar and the same is otherwise.
If you are not using the electronics on the guitar you can simply remove the battery and keep it aside. Another benefit is that you get an inbuilt tuner in many electro acoustic guitars available in India, thus avoiding the need to carry an external tuner.
So the conclusion is that the type of Guitar is more as per your needs and plans, and not really a general opinion. India is now seeing a lot of hobby guitar players and hence acoustic guitars are the most sold. Asses your plans and make a purchase accordingly. Most importantly choose a trusted brand and you will get the best out of it in years to come.