This transformer is typically either 60 Hz or 50 Hz running from a wall socket or from commercial AC. Isolation is commonly listed as a voltage rating for shock safety.
Line - Line Autotransformer
Very similar to the line - line isolation transformer but without electrical isolation between the primary and secondary. Frequently used to slightly step-up or step-down voltage to allow for use of smaller core and coil (e.g. stepping up from 208 Volts to 240 Volts or stepping down from 240 Volts to 220 Volts).
Audio Isolation Transformer
These transformers are often used to distribute an audio amplifier's output to multiple speakers.
Current Sensing Transformer
These transformers sample high current through the primary and deliver an exact replica to the secondary at a lower current. May be high or low frequency, but are frequently in the 10KHz to 1MHz range. Minimum isolation voltage is often required between primary and secondary.
Voltage Sensing Transformer
Like current sensing transformers, voltage sensing transformers sample high voltage through the primary and deliver an exact replica to the secondary at a lower voltage. They are most often used for line frequency applications at 50 Hz and 60 Hz, but the range can be as wide as that of the current sensing transformer. Minimum isolation voltage is often required between primary and secondary.