Phrasing

Phrasing is how well you play (musical) phrases. It sounds stupidly exactly as what it says on the tin, but it's exactly what it is.

The main advice is to avoid reading one note at a time, and instead read a whole phrase at once, and start singing like it's a sentence.

This is also a technique in sight reading (and improvisation). Because now by reading the whole sentence, you get an idea when the phrase starts and ends and make educated guesses.

Playing without phrasing will make you sound like a robot.

Even notes that are just basic four on the floor can be phrased.

That probably sounded very vague, so if we want to drill into the specifics...

It's basically how well you perform ADSR (Attack, Decay, Sustain, Release), and how well you connect and bend each note into each other even without specific instructions on the sheet so that it sounds like you are speaking.

Of course, before you can do all that, you need to learn to read fast enough first...

Even breathing can be part of your phrasing, the point is, you should sound like you are speaking a sentence!

Subtopic: Rubato

Rubato is playing "out of time", but still in time. This means you won't be following the sheet music strictly, but you will still give and take time as needed!