4G means LTE or WiMAX, but this is sometimes false. 4G+ Means LTE-Advanced aka True 4G, and it is faster than 4G. The only difference is the maximium theoretical speed, bandwidth and minimium latency you can get. 4G can reach speeds up to 100Mbit/s, while the 4G+ (LTE-A) can reach up to or over 1GBit/s, with less than a few milliseconds of latency.

With the faster speeds (and lower latencies), you can watch a lot of HD movies at once, do some live online gaming, and much more.

LTE needs to achieve up to 1Gbit/s of throughput (low mobility) or 100Mbit/s (high mobility) to fulfill IMT-Advanced requirements. In reality, average is between 5–50Mbit/s due to increased usage and congestion.

LTE is not true 4G. It is simply an upgrade from existing 3G networks using different air interface (OFDMA) and core network.

Hope it was informative.