Internal fragmentation refers to the wastage of memory within a partition due to a difference in size between the partition and the object resident within it.

Explanation:
When memory is allocated to a process, it is divided into fixed-sized partitions. Each partition can hold a specific size of data or process. However, the size of the data or process may be smaller than the size of the partition. This difference in size results in internal fragmentation.

Here is a detailed explanation of internal fragmentation:

1. Memory Partitioning:
- Memory in a computer system is divided into fixed-sized partitions to allocate resources.
- Each partition has a specific size, and processes are allocated memory within these partitions.
- The size of the partitions can be equal or different based on the system's design.

2. Allocation of Memory:
- When a process is loaded into memory, it is allocated a partition based on its memory requirements.
- If the size of the partition is larger than the size of the process, the remaining space within the partition remains unused.
- This unused space is known as internal fragmentation.

3. Wastage of Memory:
- Internal fragmentation results in wastage of memory.
- The unused space within a partition cannot be used to accommodate other processes or data.
- As a result, the overall memory utilization decreases, and the system's efficiency is affected.

4. Effects of Internal Fragmentation:
- Decreased Memory Utilization: Internal fragmentation leads to a decrease in memory utilization as some partitions are not fully utilized.
- Reduced Performance: The presence of internal fragmentation can cause slower memory access and slower execution of processes.
- Increased Memory Overhead: The wastage of memory due to internal fragmentation increases the memory overhead required to store processes.

5. Solutions to Internal Fragmentation:
- Compaction: It involves moving processes within memory to eliminate fragmentation and create contiguous free space.
- Coalescing: It merges adjacent free memory blocks to create larger free blocks that can accommodate larger processes.
- Dynamic Partitioning: Instead of fixed-sized partitions, memory can be divided into variable-sized partitions to reduce internal fragmentation.

In conclusion, internal fragmentation occurs when there is wastage of memory within a partition due to the difference in size between the partition and the object resident within it. It can impact memory utilization and system performance, but can be mitigated through techniques like compaction, coalescing, and dynamic partitioning.