90-degree Ells. Note the difference between the two. For uniformity in your project, get all the same fittings. Too, different brands can have different stop depths which will make your measurements off a bit.

45-degree Elbows. Again, notice the difference. The top Elbow is shorter than the bottom one, which can throw your measurements off, thus making your project out of whack.

Tee

Cross

Threaded Male & Female Connectors

Connector

End Cap

Family Portrait: Most Common PVC Fittings

Family Gathering of Furniture Grade PVC Fittings. End Cap is in the Middle. Slip Tee, Lower Middle. Notice How the Ends are Beveled for a Cleaner, Sleeker Look.

The Slip Tee is Useful for Making Hinges and Whatever Else You Can Imagine. The Tee Rotates Around the Pipe.

These are Furniture Grade Internal PVC Fittings. To My Knowledge, They're Available Only at Available Plastics (apiplastics.com). The Odd-Looking Thing at the Bottom is a Chaise Lounge Positioning Bracket.

I Painted One Internal PVC Fitting So You Can See How It Looks.