A Phrase is a short musical idea, you could see it like a sentence in a lauguage. Examples of short phrases are riffs and short melodies. Solos are made up of solos.
For this article a brief outline with some tips how to improve your phrases and, hopefully, your solos.

Most common phrases are being created out of scales such as Pentatonic scale or Diatonic scale. Most people who will use this approach end up sounding like any other guitar player. Working on your solos takes time and effort. It helps if you know what you sound like and what you can do to change this. Have a look at the next four point to improve your prhases:

                  Playing Over One String:

You may not have heard this for the first time, but playing over one string is an eyeopener for most beginners: You can see how your notes move up and down the fretboard. When you play your phrases in position you do not have this visibility and clarity of how your notes move up and down. When you try this approach sing one simple idea, and then develop it by moving up or down the fretboard instead of using your fingers to play a scalepattern you have memorized. You want every solo you play to be musical and mememorable instead of them being random noise made up of notes.

                 Play Same Phrase but now in Position:

Using the same phrase you played over one string, now transfer this idea across over various stirngs. You will now be playing in position and can probably see some scalepattern underneath your phrase. Being able to see a scalepattern will help you to familiarise your idea. Play it in position until it is smooth, then play same idea again but now over one string to see how it sounds and feels.

                 String Skipping:
          
Play Same Phrase now using string-and position skipping. Your idea may have changed a little in sound, try to keep your idea as close to your original phrase. The stringskipping may be hard at first, most people do find this not easy in the beginning: Fingers will get stuck between strings, plectrum may not sound as smooth anymore. All things you can work on individually to get it to sound good and smooth and clean.

                Using Hammer-Ons, Pull-Offs and String Bending:

Play same idea again, but jazz up your idea to add some drama to your solo by using some hammer-ons and pull-offs or even some string bending. Any of those techniques will add more flavour to your phrasing. Again, if you have never used any of these techniques before you know what you can work on.

When you listen to any solos you like you will hear that most of the above ideas are being used at one time or another. When you play solos it should become second nature to develop a good taste, technique and approach to how you can get the best out of your notes instead of playing that same old, minor Pentatonic idea without giving your notes any thought.
Keep working at some of the ideas mentioned above and over time your will start to see the change in your playing.

Happy Playing
Eddie