Knowing what drill bit to use and when to use it means you are more likely to get the job done quicker and more efficiently. However, with so many types and styles of drill bits available, this can be very confusing.
Below are the main types of drill bits, along with their features and when is best to use them

What size to use
Drill Bits are designed to make a hole in material, and they come in many shapes and sizes to suit different applications – some are more suited to cutting certain materials than others. Some also create precise and accurate holes, whilst others are designed for creating rough ones.
It is important to choose the drill bit based on what material you are cutting along with the size and depth of the hole and finish you wish to receive.

Each drill bit comes with 3 common measurements that you need to consider when choosing the correct one:

• The Diameter – this is the size of the tip or how big you wish for the hole to be drilled
• Working Length – this is the depth of the hole it will be able to drill
• Total Length – this is the total length of the drill bit including the shank.

Once you know the size, it is then easier to choose one for the specific material you are drilling

Wood
One of the most common applications you will come across is drilling through wood. There are different types of wood drill bits, and each have a different purpose:

• Auger Bits – They have a sharp point on their tip which aids in precisely drilling a hole. Their head is a spiral shape which is designed to pull the drill bit into the wood when drilling so there is no excessive pressure. Auger Bits drill deep, neat and smooth holes that are uniform all the way through. Also, their wide flute design prevents them from becoming easily clogged.
• Flat Wood/Spade Bits – These are commonly known as the same thing, and they are the best drill bit for making rough and large holes in the wood. Larger Diameters are also available which is best suited to creating holes for items such as Cables or Wires. The downfall of this, is that they leave a rougher finish compared to other drill bits and can also cause splintering if driven straight through a piece of timber. 
• Twist Drill Bits for wood – These Drill Bits are often made from HSS for a long life and durability. They are standard bits for wood designed to make simple holes, but they are also available for metal, plastic, and more materials. By using Twist Drill Bits, they provide a clean and neat finish and come in a wide range of sizes to select from.

What Drill Bit is used for Metal?
Standard HSS Cobalt Drill Bits are the best choice for drilling metal. This is for High-Speed Steel Cobalt, and they are great for harder woods and metal. They are long-lasting and durable, also are resistant to heat meaning that they can be used at faster speeds compared to other drill bits. This is one of the quickest and most effective drill bits.

What Drill Bit for Masonry?
It is inevitable that you need a harder wearing drill bit when drilling through tough materials like masonry. Masonry Drill Bits are ideal for brick, limestone, and concrete drilling. They are robust and durable, that is usually made from tungsten carbide for a longer life. It is recommended that they are used at a slower speed to prevent the bit from overheating. Like other drill bits, they come in a variety of sizes and styles.

Options available are SDS Plus, SDS Max, and SDS Rebar depending on the type of drill you are using

Other Types of Drill Bits
You can also find multi-purpose drill bits, and these do exactly what they say. They are suitable for everyday use, able to drill through a variety of different materials which means you do not have to purchase a number of drill bits for different jobs, and they can also drill through wood, metal, plastic, and masonry with ease.

Countersunk Drill Bits are used to create countersunk holes that flat-headed screws will sit flush against. The countersunk bit drills a hole in which when the screw is inserted, it can be positioned in line with or just below the surface of the material being worked on. They are great for use in woodworking applications.

Diamond Core Drill Bits are similar to Hole Saws, only they are manufactured with diamonds to provide excellent cutting efficiency and lifetime. They are used to drill large holes in tough materials and can do so with ease due to their quality construction.