Inverters are used for converting DC power from your battery banks and panels to AC power for your 230V home appliances and tools.
There are three main types of inverters Low frequency and High Frequency Modified Sine wave .
Modified Sine wave are the cheapest and smallest but the power they output is not great for electronics it heats up motors and transformers often reducing their life span and can also lead to interference in audio equipment and other sensitive electronics.
Low frequency and High Frequency pure sine wave inverters produce a great 230V AC power often better than the power you get from your utility company. The main difference between low and high frequency is transformer size Low frequency uses larger transformers thus they are heaver and often more expensive but are capable of handling much higher surge power (i.e a freezer compressor or large power tool starting up) for longer periods.