The main difference between a trowel and a float lies in their primary functions and the materials they are designed to work with:

1. **Trowel**:
- A trowel is a handheld tool with a flat, pointed metal blade attached to a handle.
- Trowels are primarily used for spreading and shaping mortar, plaster, or other similar materials during construction or masonry work.
- Bricklayers and masons use trowels to spread mortar evenly on bricks or blocks, and to scrape off excess mortar from surfaces.
- There are different types of trowels for various purposes, such as brick trowels, pointing trowels, and finishing trowels, each with specific blade shapes and sizes suited for different tasks.

2. **Float**:
- A float, also known as a masonry float or plaster float, is a flat tool typically made of wood, plastic, or metal with a handle attached.
- Floats are primarily used for smoothing and leveling the surface of freshly applied plaster, stucco, or concrete.
- Masonry floats have a flat surface that is larger and broader than that of a trowel, allowing for greater coverage and smoother finishes.
- Floats are commonly used to achieve a smooth and uniform texture on walls, ceilings, or other masonry surfaces, particularly when working with wet or freshly applied materials.

In summary, while both trowels and floats are handheld tools used in construction and masonry work, trowels are primarily used for spreading and shaping mortar or plaster, while floats are used for smoothing and leveling surfaces, such as walls or ceilings, with wet or freshly applied materials.