Adobe Premiere Pro has a vast range of transitions, in this article I will demonstrate what are Premiere pro transitions and what they do by showing preview of the Premiere transitions and  show how to apply them to your footage.

What are Premiere Pro Transitions?
My quick definition is that Premiere Pro transitions presets help you to connect two pieces and multiple of footage, images and audio clips in order to have smooth and seamless effects between them.
Hopefully the Premiere Pro transitions presets preview animations below will speak for themselves. Just click on each tab below to preview all of them.

Premiere Pro Transitions
cube-spin-premiere-transition flip-over-premiere-transition
Cube Spin Flip Over
additive-dissolve-premiere-transition cross-dissolve-premiere-transition dip-to-black-premiere-transition
Additive Dissolve Cross Dissolve Dip To Black
dip-to-white-premiere-transition film-dissolve-premiere-transition morph-cut-premiere-transition
Dip To White Film Dissolve Morph Cut
non-additive-dissolve
Non-additive Dissolve
iris-box-premiere-transition iris-cross-premiere-transition iris-diamond-premiere-transition
Iris Box Iris Cross Iris Diamond
iris-round-premiere-transition
Iris Round
pagepeel page-turn
Page Peel Page Turn
band-slide-premiere-transition center-split-premiere-transition push-premiere-transition
Band Slide Center Split Push
slide-premiere-transition split-premiere-transition
Slide Split
band-wipe barn-doors checker-wipe
Band Wipe Barn Door Checker Wipe
 checkerboard  clock-wipe gradient-wipe
CheckerBoard Clock wipe Gradient Wipe
 inset  plaint-splatter pinwheel
Inset Paint Splatter Pinwheel
radial-wipe random-block  random-wipe
Radial Wipe Random Blocks Random Wipe
 spiral-boxes venetian-blinds wedge-wipe
Spiral Boxes Venetian blinds Wedge Wipe
 wipe  zigzag-block
Wipe Zig-Zag Blocks
cross zoom premiere transitions
Cross-Zoom

You can also preview the premiere pro transitions on the youtube video below

00:02 – Cube Spin
00:05 – Flip Over
00:08 – Additive Dissolve
00:11 – Cross Dissolve
00:14 – Dip to Black
00:16 – Dip To White
00:20 – Film Dissolve
00:22 – Morph Cut
00:25 – Non Additive Dissolve
00:28 – Iris box
00:31 – Iris Cross
00:33 – Iris Diamond
00:35 – Iris Round
00:39 – Page Peel
00:41 – Page Turn
00:44 – Band Slide
00:47 – Center Split
00:50 – Push
00:53 – Split
00:55 – Slide
00:58 – Band Wipe
01:00 – Barn Doors
01:03 – Checker Wipe
01:05 – Checker Wipe
01:09 – Clock Wipe
01:11 – Gradient Wipe
01:14 – Inset
01:16 – Paint Splatter
01:19 – Pin Wheel
01:23 – Radial
01:25 – Random Blocks
01:29 – Random Wipe
01:31 – Spiral Boxes
01:35 – Venetian Blinds
01:38 – Wedge Wipe
01:41 – Wipe
01:45 – Zig-Zag Blocks
01:48 – Cross zoom

How to add a Premiere transitions to your video?

– Go to the Effects window
– Click on Video Transitions
– Select a Transition
– Drag the transition between your 2 Clips

for more info go to: https://helpx.adobe.com/premiere-pro/using/transition-overview-applying-transitions.html

How to Add new Premiere Pro transitions presets ?
Once you become an advance User at Premiere Pro I am sure you will want to have better transitions so you can impress your clients, family… below a screenshot how to import.
import-premiere-pro-preset

Also below a couple of website that provide Free Premiere Presets prfpset files
Glitch Presets from MotionArray
Color Grading Central
– Indietips

Or you have the budget you can find below some awesome Premiere transitions templates

Premiere transition pack template Premiere Transition Glitch
140 Premiere transitions effects 2D premiere pro transition template