The output voltage-current (v-i) characteristics of an enhancement type MOSFET can be divided into two regions: an ohmic region at low voltage values and a saturation region at high voltage values.

1. Ohmic Region:
- In the ohmic region, the MOSFET behaves like a resistor.
- When a positive voltage is applied between the drain and source terminals (VDS), and a positive voltage is applied to the gate terminal (VGS), the MOSFET is in the ohmic region.
- In this region, the MOSFET acts as a variable resistor, and the drain current (ID) is directly proportional to the drain-source voltage (VDS) according to Ohm's law (ID = VDS/RDS), where RDS is the resistance of the channel.
- The resistance of the channel depends on the gate-source voltage (VGS). As VGS increases, the channel resistance decreases, resulting in an increase in ID.

2. Saturation Region:
- In the saturation region, the MOSFET behaves like a current source.
- When the drain-source voltage (VDS) is high enough and the gate-source voltage (VGS) is also high, the MOSFET enters the saturation region.
- In this region, the MOSFET acts as a current source, and the drain current (ID) becomes relatively constant and independent of VDS.
- The saturation region is characterized by the MOSFET being fully turned on and operating in its active mode.
- The MOSFET is able to maintain a constant ID because the channel is already fully conducting, and further increase in VDS does not significantly affect the current flowing through the channel.

Explanation:
- The enhancement type MOSFET operates in two distinct regions: ohmic region and saturation region.
- At low voltage values, the MOSFET operates in the ohmic region, where the drain current is directly proportional to the drain-source voltage.
- At high voltage values, the MOSFET operates in the saturation region, where the drain current becomes relatively constant and independent of the drain-source voltage.
- It is important to note that the transition between these two regions depends on the applied gate-source voltage (VGS). For the MOSFET to enter the saturation region, both the drain-source voltage (VDS) and gate-source voltage (VGS) must be sufficiently high.